ITER, a first-of-a-kind nuclear tokamak, is being constructed by a partnership between China, European Union, India, Japan, Korea, Russian Federation and USA, in southern France. The buildings are well under construction and the tokamak components, largely supplied in kind by the partners, will start arriving at the end of this year. Component assembly activities start in 2018 and continue...
By combining resistive polyhelix and Bitter inserts with a large bore superconducting outsert, the new hybrid magnet in construction at LNCMI-Grenoble will produce in a first step, an overall continuous magnetic field of 43 T in a 34 mm warm bore aperture. After a brief reminder of the specificity of hybrid magnets, namely the strong electromagnetic and mechanical couplings between resistive...
In this study, a 3D multi-filament FEM model is developed for some kinds of superconducting strands, such as LMI strand, SMI-PIT strand and Bi2212 round wire. Some important factors, such as the initial thermal residual stress, the breakages of superconducting filament and twist pitch (for LMI, SMI-PIT) are taken into account. In this FEM model We calculate this thermal residual stress system,...
The twisted, stacked-tape cabling method allows developments of high current REBCO cables for various high field applications, such as fusion magnets, magnetic resonance imaging (MRI) devices and accelerator magnets. The single tape performance under applied loads is crucial to understand cable limitations, and important for choosing an appropriate cable geometry. In this paper, we...
The National High Magnetic Field Laboratory (NHMFL) has commissioned a 36.1 T magnet with homogeneity and stability of 1 ppm over a 10 mm diameter spherical volume to be used for solid state NMR. Most NMR magnets use single strands of superconducting wire carrying a few hundred amps and persistent joints and switches. This magnet uses a 20 kA superconducting cable in a steel conduit for the...
Fatigue failure had recently occurred on a 60T pulsed magnet at the Wuhan National High Magnetic Field Center (WHMFC). It was designed to produce a peak field of about 63T and had practically endured a total number of 2124 shots with 573 of them above 56T. In this paper, the cause of failure is numerically analyzed using the conductors and reinforcing fibers at the mid-plane of the magnet. The...
INFN is developing at LASA lab (Milano, Italy) the prototypes of five corrector magnets, from skew quadrupole to dodecapole, which will equip high-luminosity interaction regions of the High Luminosity-LHC (HL-LHC). These magnets are based on a superferric design, to allow a relatively simple, modular and easy to construct magnet. This program takes place within the framework of a collaboration...
The luminosity upgrade of the Large Hadron Collider requires that the new separation/recombination dipoles D2 shall deliver a field integral of 35 Tm. A design has been developed of a twin dipole generating a magnetic field as high as 4.5 T in apertures of 105 mm and 7.78 m magnetic length. The magnetic field direction is identical in both apertures causing a not negligible magnetic cross...
Functional diagnostics of superconducting magnets is essential for ensuring their safe and reliable operation and understanding performance limitations. Among various known diagnostic approaches, acoustic techniques being non-invasive and inexpensive carry a significant potential that is not yet fully explored. Firstly, acoustic emissions provide direct access to magnet mechanical disturbance...
The Large Hadron Collider (LHC) at CERN has been operating and producing physics since September 2008, and has entered after a first long shut down its second, 4-year long physics run. The LHC is to date the largest superconducting installation, counting some 10000 magnets along its 27 km long circumference. A significant operational experience has been accumulated, including the occurrence...
In 2007 the Nijmegen High Field Magnet Laboratory has embarked in a programme to design and construct a 45 T hybrid magnet to provide the highest magnetic field available to its user programme. We present the final design of the resistive insert coils for this hybrid, which will operate in the 12.3 T background field of the superconducting outsert magnet. The insert magnet has an outer...
This paper presents electromagnetic design and 3D finite element analysis (FEA) results to develop prototype machine system for the high-temperature superconducting (HTS) rotating machine integrated with a contactless HTS excitation device (CHED). This is connected and integrated on the same shaft of the rotating machine and charge the HTS field coils by pumping magnetic flux with non-contact...
In this paper, we present results, experimental and analytical, of a small-model study, from which we plan to develop and apply a full-scale field-shaking system to minimize or even eliminate the screening current-induced field (SCF) in the 800-MHz HTS Insert (H800) of the MIT 1.3-GHz LTS/HTS NMR magnet (1.3G) currently under construction—the H800 is composed of 3 nested coils, each a stack of...
As a vertical transportation apparatus for moving people and goods between floors, the elevator or lift plays an increasingly important role in the high-rise buildings. The requirements for fast velocity, comfort ability, reliability and safety issues become higher and higher. Due to its inefficiency and complicated operating system, the conventional cable elevators, which usually utilize...
Repetitive Flat-top Pulsed High Magnetic Field (RFPHMF) could widely be applied to biology, materialogy, iatrology, condensed matter physics, and many industrial applications. Nowadays, the development direction of the RFPHMF focuses on accelerating the magnetic field establishment, elevating the pulse amplitude, extending the pulse duration, enhancing the flat-top precision, boosting the...
Programmable logic and integrated technologies, as SoC, FPGA and DSP, have became mature enough to be employed in high performance magnet power supply applications. The use of a configurable mixed current and voltage digital control, combined with adaptable complex algorithms for protections (e.g. quench in superconducting magnets) and auxiliary integration (e.g. transverse flux density in a...
We have designed a 500 A class high temperature superconductor (HTS) current lead using Bi2223/AgAu tapes for a conduction cooled superconducting magnet. The HTS current lead consists of two terminal blocks, a support tube, and seven Bi2223/AgAu tapes with support tapes. An operating condition is 500 A at 70 K, 0.6 T by conduction cooling, and heat leakage through the current lead is 0.32 W...
For the improvement of the critical current density of a multifilamentary Nb3Sn strand, a high integrity of Nb filaments should be obtained by the optimal cold-drawing process for reducing the cross-section of the filaments. However, as the number of drawing cycles increases, the strain-hardening exponent of the Nb filaments also increases, which consequently hinders the area reduction, and...
Recent studies on no-insulation (NI) winding techniques for high temperature superconducting (HTS) coils have demonstrated that an NI coil has a self-protecting feature: a localized quench heat inside the coil can be automatically diverted in the radial direction owing to the absence of turn-to-turn contacts. The obvious benefits of NI may resolve difficulties in the protection of the HTS...
This paper proposes an optimal control algorithm through lateral displacement and yaw angle in curved road of shallow-depth subway systems. In the case of the surface transportation, which has recently been introduced, severe curved driving performance is required for the downtown. The existing researches are the main research theme of the lateral displacement restoration control, but there is...
This paper proposes an algorithm to obtain better results in the integrated control by reflecting the characteristics of the individual control of the front wheel and the rear wheel of shallow-depth subway systems In the case of the surface transportation, which has recently been introduced, severly curved driving performance is required for the downtown. It is possible to decrease the curve...
BLDC motors and controllers are used in many industrial fields due to the decline of permanent magnet price and the lower cost semiconductor devices. The BLDC motor is easy to maintain as compared to the DC motor and has the advantage of small size, high power, low noise, etc. The BLDC motor is generally used a lot of 120degree energizing method. Also, this motor is commonly controlled by a...
Electrification of urban transportation systems has been considered as the most promising solution for reducing the air pollution, the oil dependence and improving the energy efficiency. Therefore, it becomes more and more popular around the world. The fundamental components in these systems are electric motors which provide the propulsion force. Practically, the electric propulsion by linear...
Frozen permeability method has been widely used in separating the PM torque and reluctance torque and calculating inductance. For conventional frozen permeability method (CFPM), only the core permeability is fixed. It is suitable for the machine applying rare-earth PM materials such as NdFeB, since the material B-H curve is linear and coincide with the recoil line. However, when dealing with...
A transverse flux single-phase tubular switched reluctance linear motor (TF-TSRLM) is proposed in the paper, and it is compared with the longitudinal flux single-phase tubular switched reluctance linear motor (LF-TSRLM) in electromagnetic thrust. The stator consists of five ferromagnetic rings that are divided by four spacer rings. On the cross section of the TF-TSRLM, a stator ferromagnetic...
Based on the Meissner effect a superconducting hollow sphere rotor is levitated in the vacuum housing. During the high speed rotation, the dynamic deformations caused by the centrifugal force and the temperature variation will generate magnetic disturbing torque on the superconducting rotor. The deformations of the rotor are analyzed and simulated by finite element method, and the deformation...
DR-SRM is a novel structure device which can be evolved from conventional SRMs with a single stator and single rotor by increasing a rotor and changing the structure of stator and rotor. The double mechanical ports and double electrical ports are formed by increasing the number of rotor. This paper presents a model for dual rotors switched reluctance motor consisting of two airgaps, an...
Recently, electronic devices using a wireless charging method are increasing with development of technology. The wireless charging method is free from the space limitation and has an advantage in mobility. However, the wireless charging method has a disadvantage that the efficiency is much lower than the wired charging method. In order to improve the efficiency of the wireless charging...
In this paper, the flux linkage curve of the second form is analyzed. The characteristic of the flux linkage is presented in the form of a high order polynomial, which makes it easier for data-fitting. The flux linkage curve of the form ψ-θ curves for different i values is analyzed. The flux linkage data of the SRM prototype is obtained on 4 specific rotor positions (0°, 7.5°, 15°, 22.5°). The...
Wireless power transfer (WPT) is of increasing interests today. HTS (high temperature superconducting) WPT has been demonstrated to be more efficient than copper WPT. In our previous work, the efficiency of WPT from a copper coil (as the transmitting coil) to a HTS coil (as the receiving coil) is lower than the efficiency of WPT from the same HTS coil to the same copper coil. Namely, asymmetry...
For the quadruple magnets, the harmonic components at reference radius can be used to express the field quality using relative harmonics which is the high harmonics components (order > 2) by 2nd component. Generally speaking, the high harmonics components have negative effects on beam focusing. Therefore, the relative harmonics should be decreased to meet a target value. However, the specific...
Due to the significant penetration of wind generation, the fast capacity resources are needed to handle the fluctuations caused by the wind generation. Battery Energy Storage Systems (BESSs) could be the solution as resources to back up the unpredictable fluctuation caused by the wind generation. However, the life cycle of batteries deployed in balancing operations could be a lot shorter...
PHiX (Plasma with Helical field initiative eXperiments) is a small tokamak to research MHD phenomena such as restraint of elongated plasma instability and protection of tokamak devices from disruption. The device has 16 toroidal field coils (TF coils) and 10 poloidal field coils (PF coils) magnets. We found that we must drive these coils for more than 5-ms and the response of PF coil current...
The degradation of transport current property by the mechanical strain on the practical Nb3Sn wire is serious problem to apply for the future fusion magnet operated under higher electromagnetic force. Recently, we developed various Zn solid solution ternary Cu-Sn alloy (Cu-Sn-Zn) matrices for the internal matrix strengthened Nb3Sn wires. Zn remained homogeneously into the matrices after the...
Recently, The use of electronic devices such as mobile phones and notebooks, tablet PCs, etc. is rapidly increasing. But, There is an inconvenience that electronic devices frequently need to be charged because battery life is short. To solve this problem, The wireless power transfer(WPT) system is drawing much attention. However, WPT system used in real life requires more research for...
The 12 GeV Upgrade Project at Jefferson Lab is complete and all new systems have met their Key Performance Parameters(KPP). The Super High Momentum Spectrometer(SHMS) in JLAB’s Hall C is an 11 GeV/c particle spectrometer with a resolution of 0.5 x 10^-4 , 4.4 milli Steradian acceptance and a +20 %/-10% momentum bite. All five SC magnets have been delivered, installed, cooled down, tested and...
Super High Momentum Spectrometer (SHMS) of Hall C, part of 12 GeV Upgrade at Jefferson Lab, is tested and complete. We will present the measured quench data and the simulated ones of the Q2/3, and Dipole superconducting magnets using the quench code of Vector Fields’ Opera-3D. A multi-channel Tektronix DPO is used to record the signals of the current, voltage of the dump resistor, and other...
Superconducting magnetic energy storage (SMES) enables to offer many technical advantages, such as high energy efficiency, quick response and great controllability, and the SMES applications in distributed renewable energy sources are critical for power systems. This paper suggests a SMES to enhance the transient performance of a 100 kW grid-connected photovoltaic (PV) generation system, and...
High pulsed magnetic field is an important basic research tool, which has been used more and more widely in physics, biology and materials. Higher magnetic field can provide more opportunities for scientist to reveal new phenomena in scientific research. Aiming to achieve a higher magnetic field, Wuhan National High Magnetic Field Center (WHMFC) has designed a power supply system for 100 Tesla...
Today, researches on the all 2G HTS magnets are actively underway in the field of high magnetic fields. No-insulation coils without insulation between turn-to-turns are very stable against quenching. The characteristic resistance of the no-insulation coil depends on the turn-to-turn contact resistance, which is an important factor determining the current ramping rate. In no-insulation coils,...
LTS magnets are typically used and kept at 4K, but when being build or retrofitted they will be at ambient temperature. Cool-down at the factory or installation site can be done using LN2 and LHe, but this is an inefficient process involving a number of operational steps. This paper described how cool-down can be achieved simpler and more efficiently using a closed loop helium gas flow. In...
Thermal siphon system is a cooling method for a large scale superconducting magnet system by circulating cryogen through cooling channel. In this paper, a small scale prototype thermal siphon system for single crystal ingot growth magnet is designed based on liquid and gas He circulation. The designed system is tested as a part of design method validation process. The cooling performance of...
An electron beam ion source (EBIS) is required to fulfill the diverse requirements of proton-beam users facilitating enhanced application. Superconducting magnet is a critical part of EBIS, and cryogenic systems are essential for the design and the operation of the superconducting magnets. Thus, this study demonstrates the development of cryostat of 7 T superconducting solenoid for electron...
Since 1992, the largest Russian cryogenic helium complex of the superconducting accelerator Nuclotron with the cooling capacity of 4000 W at 4.5 K has been operating at JINR in Dubna. The construction of this high efficient cryogenic system included a large number of technical ideas that had never been applied before in the world: the fast cycling superconducting magnets, cooling by the...
The superconducting joint technology used for high-temperature superconductors (HTS) is key for realizing persistent operation of HTS magnets. Recently we have succeeded in developing a superconducting joint between REBCO conductors using a polycrystalline intermediate, which has a critical current (Ic) of >100 A at 77 K [1]; A REBCO micro-polycrystalline intermediate was prepared on the...
Bearingless motors (BMs) with built-in magnetic bearings are receiving more and more attention. Compared with other types of BMs, the bearingless synchronous reluctance motor (BSRM) has been extensively investigated due to its advantages of simple structure, low cost, low temperature rising and high speed drive. The BSRM is a typical nonlinear multivariable system. There is a strong magnetic...
Electromagnetic forming (EMF) is acknowledged as a potential forming method because of its advantages relative to traditional forming technique. However, the multi-physics coupling process makes it a daunting task to analyze the forming mechanism. It is necessary to decouple the effects of velocity and thermal in EMF. Since the electromagnetic ring expansion is used as a one-dimensional...
High temperature superconductors (HTS) have become a viable option for high field magnets, mainly due to its superior in-field current carrying capacity at greater than 20 T. However, the price of HTS conductors is still high and impedes widespread use. Provided that the need for a defect-free “long” piecelength of HTS conductor is a primary cost driver for most applications. Results...
Currently, the tubular linear permanent-magnet machine has been increasingly adopted for active vehicle suspension, since it has zero net radial force between the armature and stator, no end-windings, and volumetrically efficient. However, it suffers from relatively low thrust force and poor fault-tolerant capability. Thus, a novel modular-stator tubular vernier permanent-magnet machine will...
The future high luminosity upgrade of the Large Hadron Collider (LHC) at CERN will include twenty 4.2 m long Nb3Sn high gradient quadrupole magnets which will be components of the triplets for two LHC insertion regions. In order to test these and four pre-production models, the vertical superconducting magnet test facility of the Superconducting Magnet Division (SMD) at Brookhaven National...
Electrical aircraft are an important area of modern engineering development to meet the increasing air travel demand while managing a reduction of dependence on fossil fuels. The challenge is exacerbated due to the high sensitivity of aircraft performance with respect to mass and therefore superconducting machines are seen as a possible solution. A key enabler is to reduce the overall size of...
This study presents the design and performance results of a pair of vapor-cooled MgB2 current leads for a 1.5 T MRI magnet developed by Kiswire Advanced Technology Ltd. in Korea. To reduce the liquid helium (LHe) consumption of the MRI system, the current leads were designed as a retractable type to be detached from the magnet operated under a persistent-current mode. From the cryogenic...
A 60T pulsed high magnetic field facility is designed for the study of magnetic material at Xi'an Jiaotong University. The pulsed high magnetic field facility is energized by two 1.2MJ/3.84mF capacitive power supplies. Each supply consists of 24 capacitor banks, a protection inductor, crowbar circuit, dump circuit. To simplify system configuration, two supplies are equipped with one charge...
In various industries, ultra-high speed motor is actively studied and developed for diverse industrial applications like generators/starters for micro gas turbines, turbo-compressor, vacuum pump and turbine generator. Electric Turbo Compounding System (E-TCS), which operates with motor/generator unit at a very-high speed, is the most realistic alternative technology that can respond to fuel...
With the increasing applications in physics, biology, chemistry and many other basic scientific fields, high-stability flat-top pulsed magnetic field is demanded for a higher field intensity and a lower ripple. To meet this demands, this paper proposes a hybrid power supply to generate a high-stability flat-top pulsed magnetic field at the Wuhan National High Magnetic Field Center. The hybrid...
High magnetic field technology has played an important role in basic scientific researches. High-stability flat-top pulsed magnetic field can meet the demands of high field intensity and high stability in modern scientific experiments. The higher stability of flat-top magnetic field would be the more benefit to the observation of experimental phenomena (such as specific heat measurement and...
Switched reluctance machines are widely used in variety application in automotive, renewable energy, aerospace and domestic appliances sectors, due to its low cost, high torque capacity, simple and robust structure. In order to improve the reliability of SRM further, a dual-channel SRM (DCSRM) was proposed and their fault tolerant capacity was verified. However, the traditional topology of...
The most important point in electromagnetic design for the drive motor design of an electric TVC(Thrust vector control) system for space launch vehicle is the right choice of the maximum allowable current density considering the heat transfer condition of the vacuum environment and light weight design through high output density design. Thermal-electromagnetic interaction analysis considering...
Abstract—With the power conversion device proposes greater efficiency and higher power, the new HTS induction heating equipment shows a wide application prospect in the future in the field of metal material through heating treatment. Efficiency analysis for the traditional induction heating and new structures for the HTS induction heating are studied in this paper. Calculation models for...
As demand for motors that are capable of high-torque direct drive operation is increasing, Vernier motor is gaining its importance. Vernier motor is a type of permanent magnet (PM) motor, which is specialized for low speed and high torque operation applications. Unlike conventional PM synchronous motor (PMSM), which generates torque mainly from fundamental flux component, Vernier motor...
INTRODUCTION: Following to the recently emerging environmental regulations and energy depletion, HEV and EV draw attention as future cars. And there are many studies carried out for traction motor design. This study is about a design algorithm which can make wound field synchronous motor design easier and faster. Because main flux path is sensitive to magnetic saturation and heat problem is...
The High Field Magnet Laboratory has designed, manufactured and tested a pair of 20 kA binary vapour cooled/superconducting current leads for the superconducting outsert magnet of its 45 T hybrid magnet system, in close collaboration with the National High Magnetic Field Laboratory (FL, USA). The resistive section of each lead consists of 22 parallel copper plates cooled by a flow of nitrogen...
Three large superconducting magnets have been designed and built by Sigmaphi (France) for the Jefferson Lab’s 11 GeV/C Superconducting Spectrometer. These SHMS Dipole and Q2/Q3 quadrupoles use the same collaring system based on aluminum force rings designed to ensure coil integrity and avoid conductor motion. The coil properties have been determined thanks to mechanical tests at room...
Institute of Plasma Physics, Chinese Academy of Sciences (ASIPP) was contracted by General Atomics Company to develop a superconducting feeder system containing a pair of 52 kA high temperature superconducting (HTS) current leads for ITER Central Solenoid （CS） magnet test. These HTS current leads are majorly based on the previous ITER lead design experiences. However, the vertical assembly...
We present a recent successful program to develop a 1.5 Tesla MRI magnet with a maximum helium inventory of less than 50 litres. The Magnet Technology Demonstrator was fully evaluated in a Siemens MRI system and found to deliver comparable imaging performance to a conventional bath-cooled magnet. As well as the development of the novel magnet technology, other key enabling technologies were...
In the frame of the ongoing design study of the Future Circular Collider (FCC), new options for detector magnets are being developed. In the current concept, the first phase of the FCC may be the FCC-ee, an electron-positron collider operating at energies up to 350 GeV in a 100 km long tunnel. As second phase it may be replaced by a 100 TeV hadron-hadron collider (FCC-hh). The particle...
A 100 MVA/100 MJ flywheel pulse generator system with the characteristics of high energy density and good control performance has been developed to energize the pulsed magnet at the Wuhan National High Magnetic Field Center (WHMFC). To realize the flexible, accurate, real-time and safe remote monitoring of the pulse generator system, a set of monitoring system using the total control plus...
For the superconducting magnetic bearings (SMB) employed with stacked high-temperature superconducting (HTS) tapes, rotational or linear, its static and dynamic performance are essential for engineering application. Up to now, most works reported on the HTS tapes of SMB were focused on experimentally or numerically studies on levitation and guidance forces under quasi-static conditions....
Surface permanent-magnet (SPM) machines with a fractional-slot concentrated winding (FSCW) present several advantages, such as high copper packing factor, short end-winding length, low cogging torque, small volume and good fault-tolerant capability, because of which SPM machines have been increasingly applied in aerospace applications. However, the key challenge of utilizing FSCW is abundant...
The dual-stator switched reluctance motor (SRM) is based on the traditional SRM and increases one electrical port with two stators and a rotor. The outer-stator adopts salient pole structure of 12 poles, the inner-stator adopts 6 poles, the middle-rotor is doubly salient with 8 poles. The outer-stator and inner-stator have concentrated windings. That is to say, the outer motor is three-phase...
For the virtues of no friction and abrasion, high-speed and high-precision, long life, and etc., bearingless motors have wide application prospects in high-purity and high-speed areas. Meanwhile, multi-phase motors are superior over three-phase motors for their higher torque density and lower torque ripple. For a five-phase motor, the torque density can be further increased when the...
In this research, we designed Interior Permanent Magnet Synchronous Motor (IPMSM) type traction motor for 130kW Electrical Vehicle (EV). In addition, we analyzed its electromagnetic characteristics related to Permanent Magnet (PM) such as eddy current loss of PM, demagnetization, electromagnetic force especially radial magnetic force, and performed the noise analysis using the noise map in...
The requested beam precision of the Facility for Antiproton and Ion Research (FAIR) requires the regular calibration of the main components of the current control system such as the Zero-Flux Direct Current-Current Transducer (DCCT) and the analogue-to-digital converter (ADC) module at a level of 1ppm or better. To reach this goal, a dedicated calibration laboratory is designed and prepared...
In the past much of the emphasis in the development of Nb3Sn superconducting strands has been on improving the non-Cu critical current density (Jc). Different design Nb3Sn strands were manufactured by the bronze route artificially doped with titanium in bronze. The influences of bronze to Nb volume ratio, filament diameter and Ti content were studied.Bronze to Nb volume ratio affected Jc...
We have developed a desktop-type superconducting bulk magnet using a Stirling cryocooler with the aim of miniaturizing the magnet system. As a result of cooling and magnetizing tests using a GdBCO bulk material 45 mm in diameter and 15 mm thick, the lowest achieved temperature was 51.3 K, and the maximum trapped field was approximately 2.8 T at the center of the bulk surface in the applied...
Permanent magnet (PM), such as NdFeB, in the interior permanent magnet synchronous motor (IPMSM) used to be irreversibly demagnetized when the motor operate at high temperature. Therefore, the motor is designed considering irreversible demagnetization of PM. However, it is difficult to optimize motor design because we can’t forecast the exact temperature of PM when the motor operate. In...
Practical Nb3Sn superconductive strands of composite material were utilized for a cable-in-conduit conductor (CICC) for ITER central solenoid (CS) which consist of 576 Nb3Sn strands, 288 Cu strands and a stainless-steel jacket. During the manufacture of CS, heat treatment up to 923 K is applied to the CICC for reaction of Sn and Nb in Nb3Sn strands. the CICC is cooled down to approximately 4 K...
For the high temperature superconducting (HTS) coils supplied by DC powers, a thermal disturbance may cause local temperature rise and irreversible damage because of constant current. In contrast, when a thermal disturbance occurs, the current flowing in a closed-loop HTS coil operated in persistent current mode (PCM) will decrease correspondingly. In this paper, a closed-loop single-pancake...
The detailed calculation of the current and losses distribution during the electrodynamic transients is of great importance for the design of superconducting accelerator magnets made of Rutherford cable. On the one hand, the current distribution affects the field harmonics generated by the superconducting magnet; on the other hand, the loss computation is necessary for the design of the...
Since MgB2 wires have been developed and commercially available, large scale cable assembled with MgB2 strands is required for fabricating Superconducting Magnetic Energy Storage (SMES) devices. To form the MgB2 superconducting material, heat treatment procedure is needed forming intermetallic compounds like Nb3Sn. In general, magnets using those types of materials are constructed in simple...
This paper analyzed the flux characteristics of a single-phase tubular switched reluctance linear motor (TSRLM) based on magnetic equivalent circuit (MEC) method. The stator is composed of a stator sleeve and a bread type winding. There are two teeth on the stator. The bread type winding is embedded in the slot of the stator, which can improve the coil factor and decrease the end effect. The...
Linear induction motors (LIMs) have been widely applied in urban transit systems, such as in metros and low-speed magnetically levitated train. Due to the inherent eddy-current loss on the secondary reaction plate, the LIM applied in urban rail transit suffers from poor power factor and efficiency. And the efficiency of the current linear synchronous motors in urban rail transit is also...
A thin superconducting solenoid is used to provide magnetic field in the CMD-3 particle detector. For power supply of the solenoid a superconducting fullwave AC/DC rectifier is designed. The rectifier is a current step-up superconducting transformer with two thermally controlled superconducting switches connected to its secondary windings. The CMD-3 solenoid is indirectly cooled, so the...
The simulation analysis of thermal and electromagnetic behaviors in ReBCO coils after a local normal conduction transition has been performed by many research groups. The numerical analysis, however, were about the behaviors after generating an initial normal spot and the occurrence factor of the initial normal conduction transition has not been sufficiently clarified yet. To clarify the...
For the high luminosity upgrade of the large hadron collider (LHC) the US accelerator research program (LARP) is developing a magnet designated MQXF and its associated 40 strand Nb3Sn Rutherford cable designated QXF. To suppress interstrand coupling currents generated during field ramp 25 μm thick stainless steel cores may be included in the QXF cables. For the present study cables with cores...
It is generally agreed that the development of a self-protective MgB2 magnet may not be achieved because of the slow normal-zone propagation velocity of the MgB2 wires, compared to their low-temperature superconductor counterparts. However, the use of the no-insulation (NI) winding technique can allow the MgB2 magnet to be self-protecting, because the excessive heat and current generated by...
In the ITER magnets consisting of Nb3Sn conductors, the magnets are fabricated through the so-called wind & react (W & R) technique. In the W & R process, the conductors are wound prior to the heat treatment to form the Nb3Sn superconducting strands from the non-superconducting ductile precursor ones. Then the heat-treated windings are encased into the radial plate keeping their winding shape...
In the framework of the French-German project Iseult, we chose to design the 4.5 K vapor cooled current leads of the 11.75 T MRI magnet using a burn-proof approach, i.e. they are able to withstand a 3-hour current slow dump without any active cooling. This constraint led us to select brass instead of pure copper, resulting in higher mass and thus in higher thermal stability. The drawback is a...
The MRI industry is reliant on persistent-mode superconducting electromagnets for high magnetic fields and increased stability. Achieving persistent coils is entirely dependent on the formation of high quality superconducting joints, currently made using Pb-Bi solder. Whilst this is an effective solution, there is legislative pressure to remove the lead even from medical instruments. There is...
For the development of CC-tapes based bearings and transportation systems it is important to have not only information on the levitation force, but also the data on stability of the system in response to the lateral displacements. This work continues series of studies on the levitation properties of CC-tapes stacks and primarily focuses on the guidance force. In our report, we present new...
The high temperature superconducting (HTS) bulk in cryostats is an important part of HTS maglev systems. For the potential application to evacuated tube transportation, it is necessary to recognize the levitation and guidance performance of the bulk under a low-pressure condition. Based on a home-made pressure-reducing platform, we have studied the levitation performance of two kinds of bulks...
For the safe operation of high-temperature superconducting (HTS) maglev vehicles, the liquid nitrogen level of the onboard cryostat should be monitored in real-time during the whole running process. The previous liquid nitrogen level detection method was proposed by using platinum resistance sensors as testing equipment and estimating the liquid level by threshold value judgment. However, the...
The "Facility for Antiproton and Ion Research - FAIR" will be built near the premises of the renowned physical research institute GSI Helmholtzzentrum für Schwerionenforschung GmbH in Darmstadt Germany. The company Luvata has been the sole supplier for low loss Superconducting wires for the SIS100 main magnets. SIS100 is a ring accelerator (heavy ion synchrotron) with a circumference of 1100...
With the introduction of new wide bore, high field magnets up to 19 Tesla at 150mm and 15 Tesla at 270mm cold bore, new large insert designs have lead to an interest in low vibration measurements with large sample sizes at low temperature. Oxford is developing a new generation of high persistence, high field, wide bore magnets moving on from the current generation of driven magnets requiring...
An magnet was manufactured and tested for a 1 MJ/0.5 MVA Superconducting Magnetic Energy Storage and Fault Current Limiter system (SMES-FCL) with HTS tapes recently. It consists of 46 double pancakes with an inductance of 13.3 H, and the rated operating current is 388 A, the maximum magnetic field is up to 3.5 T. In this paper, the fabrication and tests of the 46 double pancakes, the...
The paper describes the result of the ITER feeder main busbar joint sample qualification test as confirmation of the requirement of busbar joint resistance; 2 nΩ at 70 kA at zero background field, as well as those of joint performance in various magnetic fields to investigate stability and current distribution characteristics in feeder-type joint box. The results support the quality of the...
The advent of new kind of superconductors can introduce a new application age. Modern magnet designs and applications push towards persistent mode system realized with multiple superconductive connected coils. The quality of field persistence is fundamental in order to characterize the goodness of the superconductive joint technical implementation. A theoretical methodology able to predict the...
The high-frequency high-voltage (HFHV) transformer acts as a key part for galvanic isolation, energy transmission and voltage conversion in high-frequency resonant converter. And the performance is highly affected by the parasitic parameters, especially the parasitic capacitance. However, the existing techniques have a lot of shortcomings when determining the parasitic capacitance of...
High pulsed magnetic field is becoming more and more widely used in physics, biology and materials. For serving scientific experiments better, a power supply system for 100 Tesla magnetic field is designed at Wuhan National High Magnetic Field Center (WHMFC). In the preliminary design, the 100 Tesla magnet consists of three coils in a coaxial structure. The outer coil is powered by...
Nb-rod-method Cu-Nb reinforced bronze process Nb3Sn (Cu-Nb/Nb3Sn) wires are applicable to React-and-Wind processed Nb3Sn coils. The Cu-Nb composite material functions as a reinforcing stabilizer during the superconducting magnet operation. Moreover, it suppresses the damage of reacted Nb3Sn filaments due to the applied stress during manufacturing process such as the pre-bending treatment, the...
Variable Flux Memory Motor(VFMM) is able to vary its magnetic field intensity of the permanent magnet(PM). Thus, VFMM has advantage for high speed operation with higher efficiency, when field intensity of PM is reduced. However, shape of the motor and arrangement of PM are important factors within restricted geometry of VFMM, because large d-axis current pulse is requisite to achieve high...
After mass production for ITER, Western Superconducting Technologies, Co. Ltd. (WST) still takes great efforts at internal-tin (IT) Nb3Sn strand with higher Jc and lower Qh, for next generation of fusion reactors, such as DEMO in Europe and CFETR in China. Three routes, i.e. Cu split, Sn spacers and 37 subelements were carried out to obtain such strand, based on the structure and process of IT...
In 2015, the first ever polarized Drell-Yan experiment was performed at the COMPASS spectrometer at CERN. A 190 GeV/c pion beam with an intensity of 108 pions/s interacted with a transversely polarized NH3 target. The hydrogen nuclei in the solid-state NH3 are polarized by dynamic nuclear polarization (DNP) in a 2.5 T longitudinal magnetic field, while the target material is cooled down to...
It is well known that critical current (Ic) of an high temperature superconductor (HTS) magnet comprising a stack of pancake coils is limited by that of "one" pancake, while the rest of the pancakes still have substantial margin to their own Ic. This unfavorable design issue is often mitigated by the so-called multi-width (MW) technique, where pancake coils wound with the narrowest tapes were...
Current leads with use of high temperature superconductors (HTS) permit to reduce sufficiently heat transfer to liquid helium in many superconducting magnets applications. They are one of the widest HTS applications. For example, in Large Hadron Collider more than 3000 units of such current leads are used providing sufficient saving of heat transfer to liquid helium. HTS current leads made of...
A coaxial magnetic gear (CMG) is a non-contact machine that is used to transfer torque and to accelerate or decelerate. This type of gear has several advantages, including no mechanical loss, no required maintenance, and outstanding protection against overload [1]. As a result, they are used in various applications, such as wind power generation and electric vehicles. However, CMGs have high...
Nuclotron-based Ion Collider state-of-art design involves innovative solutions in superconductive applied technology. Thanks to its consolidated experience, ASG has been directly involved into the program by providing to Joint Institute for Nuclear Research (JINR) a large 0.5 T Nb-Ti superconductive magnet equipped with an active (resistive) modulation system. Typical solutions have been...
The Karlsruhe Institute of Technology (KIT) agreed to construct and test the High Temperature Superconductor Current Leads (HTS-CL) for the tokamak JT-60SA presently under construction in the frame of the Broader Approach agreement between Europe and Japan. In total 6 HTS-CLs for 25.7 kA for the TF coils and 20 HTS-CLs for 20 kA for the PF and CS coils are required and all of them have to be...
HTS superconducting magnets for MRI or NMR should be operated in persistent current mode to achieve high homogeneity and stability. A persistent current switch and a superconducting joint are the key technologies for persistent current operation. Recently, a superconducting joint has been fabricated successfully in Furukawa Electric Co., Ltd. We made a persistent current system including the...
This study focused on efficiency improvement of BLDC motors via reduction of torque ripple, core loss, and permanent magnet loss. To achieve this objective, we proposed an improved 150° commutation method for three-phase permanent magnet brushless DC (BLDC) motors to improve the current waveform. Although the 120° commutation method is generally employed for a BLDC motor, the 150° commutation...
Second generation (2G) high temperature superconducting (HTS) tapes are now capable of carrying very high transport current and promising for a wide range of applications. A large-capacity wind generator prototype has been developed using HTS tapes. The racetrack coils wound with 2G HTS tapes are used in the rotor, whereas the conventional technology is employed in the stator. The reliability...
When a high temperature superconductor (HTS) magnet consisting of a stack of pancake coils is wound, precisely controlling both the outer diameter and number of turns in the coil is difficult, mainly due to manufacturing uncertainty of the HTS tapes. To “arbitrarily” adjust the number of turns in each pancake is often adopted to precisely control the outer diameters, which obviously...
Advances in HTS technology have the potential to enable high field magnets with fields in excess of the maximum obtainable with purely LTS magnets. HTS insert coils may be operated in the bore of a high field LTS magnet, or ‘outsert’, in order to enhance the overall central field. The HTS inserts are usually operated at the same low temperatures as the LTS coils as this allows a common cooling...
The high luminosity upgrade project US LARP/HiLumi has successfully tested the first 1.5 m prototype quadrupole MQXFS1 at Fermilab’ Magnet test facility. Several thermal cycles and test programs were performed, with different pre-load configurations. To localize the quenches a quench antenna and the information of the voltage taps is used. The Quench Antenna was placed in the warm bore of an...
Cea Saclay, in collaboration with the French SMI Sigmaphi, have fabricated a 50 kg solenoid with 2 km of Columbus MgB2 rectangular wire (3*0.7 mm²). The magnet was powered with 100 A at about 10 K and reached 4.2 T on the wire, with an external magnetic field of 3 T. A comparison between the protection and stability theoretical study and experimental results is presented. The quench...
Since 2010 to present, several sub-size magnet assemblies, designed as test beds for impregnated Nb3Sn-based coil technology validation, are tested at the CERN Superconducting Magnet Test Facility (SM18). These Short Model Coils (SMC) and Racetrack Model Coil (RMC) have been used to characterize two types of Rutherford cables foreseen for the coils of the Nb3Sn magnets for the HL-LHC and High...
The planned upgrade of the LHC collimation system requires the installation of 11 T Nb3Sn dipole magnets. Due to the large stored energy density and the low copper stabilizer section, the quench protection of these magnets is particularly challenging. A total of ten coils assembled in five single aperture and two double aperture short model magnets have been tested at CERN with different...
For the upgrade of the booster of the European Synchrotron Radiation Facility in France, an IGBT based ramping current injection system for the dipole electromagnets has been developed, delivered and commissioned. The main function of the dipole power supply is to drive the necessary voltage for an accurate 4 Hz triangular current wave injection in the electromagnets with peak value of current...
In Wuhan National High Magnetic Field Center, a new explosive DC breaker switch based on the pulsed electromagnetic forming (EMF) technology is developed to shut down the Battery Bank power supply for protecting the long pulsed magnetic field system when terrible fault happens. The switch is reformed from the aluminum wire electrical explosive switch of the Laboratoire National des Champs...
Pulse generator is one of the common power supply for flat-top pulsed magnetic field for its advantages of large energy storage and flexible control. However, some characteristics of pulse generator, such as nonlinearity and time-varying, limit the effect of measures by optimizing control strategy to improve the stability of flat-top. On the base of pulse generator power supply system for...
A magnet composed by three coaxially nested coils has been developed to generate 100 Tesla pulsed magnetic field at the Wuhan National High Magnetic Field Center (WHMFC). The flywheel generator system has great energy storage density and can control the waveform of the magnet current, therefore the outer coil is energized by a 100 MVA/100 MJ flywheel pulse generator. To reduce the magnet heat...
The electrical interconnections between the LHC main magnets are made of soldered joints (splices) of two superconducting Rutherford cables stabilized by a copper busbar. In 2009, a number of splices were found not properly stabilized and could have burnt through in case of quench at high current. The LHC was therefore operated at reduced energy and all Rutherford-cable joints were...
A rig was fabricated to test single-strand excitation and current sharing in Nb3Sn Rutherford Cables. Measurements were performed on a 40 centimeters length of 27-strand cored and non-cored cables which were mounted on a U-shaped holder. Samples were reacted and epoxy impregnated using magnet-like protocols. Current was injected into a single strand at varying I/Ic and a heat pulse was used to...
In the traditional magnetic bearings, displacement sensors are used to estimate position of rotors, which increase size and cost of magnetic bearings, and decrease its dynamic performance. The soft sensing technology can not only solve the problems above, but also eliminate the mutual coupling of motion equations, which makes the design of controller easier. As a result, soft sensing...
We present the current status of design, testing and manufacturing of the magnet system of the PENeLOPE neutron lifetime measurement experiment, carried out by Babcock Noell GmbH on behalf of and in close cooperation with Technical University of Munich. Ultra cold neutrons produced by the experimental reactor facility in Garching are stored in a large volume magnetic bottle and held confined...
It has previously observed that superconducting magnets have been conventionally excited by a unified current which limited by the largest perpendicular magnetic field usually on the top of magnet due to anisotropic properties . In this case, the current carrying capacity of these pancake windings except that on the ends of the magnet can’t get fully used .This paper provides a new method to...
An apparatus is constructed for Nb3Al short wires heat treatment with rapid heating and quenching (RHQ) method. Multifilamentary Nb/Al precursors are fabricated by rod-in-tube (RIT), powder-in-tube (PIT) and jelly-roll (JR) processes. These precursors are RHQ heat treated in the apparatus and then transformation heat treated at 800 °C for 10 h in a vacuum furnace. Transport and magnetization...
MgB2 wires with Tc ~ 39 K has been developed for the applications such as various coils. Considering hydrogen society in the future, MgB2 coils for the Superconducting Magnetic Energy Storage (SMES) devices under conduction cooling are worth serious consideration. First, the authors evaluated critical current density in commercially available MgB2 wires as a function of magnetic field and...
Recently, As environmental problems such as global warming have appeared, MPES (Minimum Energy Performance standard) that regulates the efficiency of industrial induction motor is being implemented centered on developed countries. MPES limits the use of induction motors less than a certain efficiency to improve the energy efficiency. There are cases where the use of induction motors below IE4...
High-temperature superconducting (HTS) tapes are expected to improve small sized high field magnets such as superconducting magnetic energy storage (SMES). The authors proposed the force-balanced coils (FBC) concept as a feasibility option for SMES. Although the FBC can minimize the mechanical stresses induced by the electromagnetic forces, the FBC has three-dimensional complex shapes of...
A facility, which will generate 100 T pulsed high magnetic field, is under development recently at Wuhan National High Magnetic Field Center (WHMFC). The pulsed magnet is composed of three coils, and driven by four power supplies of three types. The outer coil is driven by the battery bank of 1620 lead-acid batteries connected in series with the 100 MVA / 100 MJ pulsed generator, The middle...
The 32T all-superconducting user magnet comprised of a REBCO tape pancake-wound dual-coil insert and an LTS multi-coil outsert has been tested at the NHMFL. The magnet protected-quench behavior was simulated using a custom-written Fortran computer code. The simulation results and their sensitivity to the input data are discussed. The effect of insert quench protection system parameters on the...
A prototype HTS (High Temperature Superconductor) quadrupole magnet of In-flight fragment separator was developed and successfully tested to generate field gradient of 9 T/m. This paper describes thermal characteristics of the quadrupole magnet. The magnet is composed of four race-track coils and each coil consists of two double pancake coils with ReBCO wires and stainless steel tape for...
A 3 T 100 mm all-REBCO multi-width (MW) no-insulation (NI) magnet was designed constructed, and currently being tested at the Korea Basic Science Institute. Key features of the magnet include use of “metallic cladding (MC)” REBCO tapes, i.e., a 1-um thick stainless steel cladding layer hermetically surrounds the tape in order to increase the turn-to-turn contact resistanc of the NI coils. The...
A REBCO pancake coils using a no-insulation (NI) winding technique is received attention. An NI winding technique greatly enhances the thermal stability of REBCO pancake coils, and it is desired to be applied to high magnetic field NMR/MRI magnet, etc. The high thermal stability of NI REBCO magnets was confirmed in many experiments and numerical simulations, even though any accident due to...
The Grenoble steady magnetic field facility is one of the four high field facilities part of the European Magnetic Field Laboratory. The upgrade of the Grenoble facility has started in 2013 and aims in a first phase at increasing the electrical power from 24 to 30 MW and to develop the high field magnets accordingly. A new 18 MW power converter has been made available to users in 2017 and...
The JT-60SA experiment will be the world’s largest superconducting tokamak when it is assembled in 2019 in Naka, Japan (R=3m, a=1.2m). It is being constructed jointly by institutions in the EU and Japan under the Broader Approach agreement. Manufacturing of the six NbTi equilibrium / poloidal field coils, which have a diameter of up to 12m, has been completed. So far 14 of the 18 NbTi toroidal...
Japanese researchers succeeded in developing a 1.02GHz NMR (24T) in 2014. The next field target is a 1.3GHz (30.5T) and we have commenced designing a high resolution 1.3GHz LTS/HTS NMR magnet, operated in persistent current (PC) mode. The basic concept and relevant technical problems are identified in this paper.
To reduce the magnet size, high current density HTS coils are used that generate...
In 2005 the Committee on Opportunities in High Magnetic Fields (COHMAG) issued a challenge to develop a 30 T high-resolution NMR magnet. In response, the National High Magnetic Field Laboratory (NHMFL) is investigating all three commercially available high-temperature superconductors (HTS) including REBCO, Bi-2212 and most recently, a reinforced Bi-2223 conductor supplied by Sumitomo...
In the framework of the EuroCirCol project the high field accelerator magnet design work package 5 focuses on double-aperture dipole magnets made of Nb3Sn conductors and providing a field of 16 T in a 50-mm aperture. Three options are considered: block-coils, common-coils and cosine-¬theta, the workload being shared between several research institutes. All options are explored and compared...
We have developed RE-Ba-Cu-O (REBCO; RE=rare earth) superconducting magnet operated in subcooled liquid nitrogen (68 K). The superconducting magnet is a stack of six double pancake (DP) coils. Each DP coil was made of a REBCO coated conductor. The conductor was insulated by polyimide tape wrappings. The width and thickness of the insulated conductor were 4 mm and 0.2 mm, respectively. The...
The construction of a full-superconducting tokamak referred as JT-60 Super Advanced (JT-60SA) is in progress under the JA-EU broader approach projects. The magnet system of JT-60SA consists of 18 toroidal field (TF) coils, 4 modules of central solenoid (CS) and 6 equilibrium field (EF) coils.
The diameter, the height, the number of layers and the number of turns of CS module are 2.0 m, 1.6 m,...
In the framework of Broader Approach program for the early realization of fusion with the construction of JT-60SA tokamak, ENEA has to provide 9 of the 18 TF coils of JT-60SA magnet system. The supply has been subsequently increased to include the procurement of an additional TF coil for spare purposes. The production of the spare coil started in 2016, after the supply to ASG of the...
Since 2014, the Korea Basic Science Institute (KBSI), the Korea Institute of Machinery and Materials, the National High Magnetic Field Laboratory, and the SuNAM Co., Ltd. have been on international collaboration to develop a 9.4 T (400 MHz $^1$H frequency) 100 mm winding-diameter metal-clad no-insulation all-REBa$_2$Cu$_3$O$_{7-x}$ (REBCO, RE = Rare Earth) high-resolution NMR magnet cooled by...
EuroCirCol is a conceptual design study for a post-LHC research infrastructure based on an energy-frontier 100 TeV circular hadron collider. In the frame of the high-field accelerator magnet design work package of this study, the feasibility of a 16-T dipole in common coil configuration is being studied. This paper shows the electromagnetic calculations performed to achieve the required field...
After LHC will be turned off, a new accelerator machine will be needed in order to explore unknown high-energy Physics regions. For this reason, the project FCC (Future Circular Collider) has started at CERN, with the target of studying the feasibility of a very large hadron collider with 50 TeV proton beams in a 100 km circumference. The EuroCirCol project is part of the FCC study under...
Nowadays, remotely-controlled catheter ablation has emerged as a novel approach to reduce fluoroscopy exposure and provide stable and reproducible catheter movement during in cardiac surgeries for arrhythmias. A remote catheter magnetic navigation system (MNS) which provides real-time navigation of the catheter in the heart is under development in IEE. The catheter navigation system consists...
JT-60SA is a fusion experiment which is jointly constructed by Japan and Europe and which shall contribute to the early realization of fusion energy, by providing support to the operation of ITER, and by addressing key physics issues for ITER and DEMO. In order to achieve these goals, the existing JT-60U experiment will be upgraded to JT-60SA by using superconducting coils. The 18 TF coils of...
A project to develop fundamental technologies for accelerator magnets using REBCO coated conductors is currently underway funded by the Japan Science and Technology Agency (JST).
In this project, an FFAG (fixed field alternating gradient) accelerator for the carbon cancer therapy system is one of the primary applications. In the first step of this project, REBCO coils with complicated winding...
The US HEP Magnet Development Program is developing accelerator insert coils based on REBCO coated conductors. These insert coils will operate in high dipole or quadrupole background fields and enhance the field generated by the outsert coils made of Nb$_3$Sn or NbTi conductors. The inserts are of canted $\cos\theta$ (CCT) design configuration, which effectively intercepts the accumulation of...
The determination of coupling losses induced in cable-in-conduit conductors (CICCs) when subject to time-varying magnetic field is a major issue commonly encountered in large fusion tokamaks (e.g. JT-60SA, ITER, DEMO). The knowledge of these losses is crucial to determine the stability of CICCs but is yet difficult to achieve analytically in a satisfying way given the specific and complex...
A HTS linear synchronous motor prototype that could be used as the traction system of high speed railway was demonstrated in our laboratory. The stator was made of traditional ferromagnetic yoke and three-phase copper windings. To control the three-phase travelling magnetic field of the stator, a frequency-variable convertor was applied to the system. Different from the permanent magnet mover...
For the past few years, notable progress has been made in the no-insulation (NI) high temperature superconductor (HTS) magnet technology. Electromagnetic (thus fast) quench propagation, the key mechanism for the "self-protecting", has been demonstrated in experiments of >100 NI modules and test coils, as well as various numerical simulations. Major drawbacks of the NI technique, including...
Due to low turn-to-turn contact resistances, non-insulated (NI) REBCO coils possess much higher thermal stability than their insulated counterparts. Experiments even showed that NI coils are in general self-protecting, recovering from a quench without external quench protection mechanisms. Recent studies showed that an uncontained local quench can amplify itself quickly, leading to an abrupt...
A straightforward analytical model is presented that describes the observed slow thermal drift of the conduction-cooled ReBCO coils developed for the EcoSwing project. In the vicinity of their critical surface, both the temperature and the voltage across these coils drift upwards in response to a current step, on a time-scale ranging from minutes to hours. Eventually, such drift results either...
A novel Permanent-magnet Machine with Counter-rotating Dual Rotors (PMCDR) is proposed in order to improve operation performance of underwater vehicle anti-rotation propulsion system. It can be substantially simplify system structure, decrease volume, reduce mass and cost, moreover, improve reliability without brush and slip-ring. The idea and principle of electromagnetic design are provided...
A portable magnet system based on bulk (RE)BCO, high temperature bulk superconductors, which constitute high-field magnets, has been designed constructed. The use of a small-volume sterling cryocooler with a base temperature of 50 K has enabled a portable and compact magnet design. The magnetization of the bulk superconductors was realized by a pulsed field magnetization (PFM) technique. The...
US Magnet Development Program (MDP) is developing a 15 T Nb3Sn dipole demonstrator for a post-LHC pp Collider. The magnet design is based on 60-mm aperture 4-layer shell-type coils, graded between the inner and outer layers to maximize the magnet performance. An innovative mechanical structure based on aluminum IC-clamps and a thick stainless steel skin was developed to preload brittle Nb3Sn...
The Cable-In-Conduit Conductors (CICCs) for the ITER magnets are subjected to fast changing magnetic fields during the plasma-operating scenario. In order to anticipate to the limitations of the conductors under the foreseen operating conditions, it is essential to have a better understanding of the stability margin of the magnets. In the last decade ITER has launched a campaign for...
The flux-reversal linear permanent magnet machines (FRLPMs) have the features of high thrust density, high efficiency and robust stator structure, which make it a suitable solution for linear traction motors, wave energy generators and linear servo motors. But the FRLPMs suffer from the doubly-salient structure and thus it is hard to further improve the flux-linkage and the thrust density of...
Demand continues to be high for high-temperature superconducting (HTS) wires and tapes to wind coils of high field quality for NMR or MRI applications. A magnet bore field mapper of relatively simple design and operation is needed to confirm the low-order spherical harmonics during testing after construction of such coils, irrespective of compensation. Presented here is one probe design of a...
Large-scaled induction furnaces for non-ferrous metal billets operated at commercial frequency have an energy efficiency of only 50~60% due to the considerable loss from the copper coils used to generate the magnetic fields. Efforts to improve their efficiency are hampered by physical limits. A DC induction heating using HTS magnets has been suggested for achieving higher energy efficiency. A...
The Normal Zone Propagation Velocity (NZPV) and quench are areas of intense research for High Temperature Superconductors (HTS). While normal zones travel with speeds in the order of magnitude of m/s in Low Temperature Superconductors (LTS), in HTS coated conductors this speed is in the order of cm/s. This makes ensuring a quick and uniform quench, and thereby the cryostability of tapes,...
Babcock Noell GmbH (BNG) and the Institute for Beam Physics and Technology (IBPT) of the Karlsruhe Institute of Technology (KIT) are collaborating in an R&D program focused on the development of superconducting undulators (SCUs). After successfully completing SCU15, a full scale 15 mm period length device installed in ANKA in 2015, the team developed SCU20 a second device with 20 mm period...
The Institute for Beam Physics and Technology (IBPT) of the Karlsruhe Institute of Technology (KIT) and Babcock Noell GmbH (BNG) are collaborating to develop superconducting undulators for ANKA and low emittance light sources. The collaboration is now focusing on a superconducting undulator with a period length of 20 mm (SCU20) planned to be installed at the accelerator test facility and...
Quench propagation and degradation properties are critical in quench detection and protection of high temperature superconductor (HTS). It is essential to understand the strain influence on quench propagation velocity (QPV) and degradation limits in HTS in practical applications since there are unavoidable for pre-strain and deformation in its manufacture and operation. In the present work,...
Small tube bulging by electromagnetic forming is a challenging issue because the coil must be placed inside of the pipe to generate repulsion electromagnetic force. To solve this problem, a novel method for forming pipe fittings by using electromagnetic attraction is proposed. To generate an electromagnetic attraction, a special current is used to drive the coil. This special current consists...
The Future Circular Collider is at the conceptual design phase and one of the main components are the high-field Nb3Sn dipole magnets targeting 16 T of bore field. With very high current densities and high stored energy, the quench protection is an essential part of the magnet design. The quench protection design relies largely on simulations and naturally, the reliability of the software is...
During the last decade nine multipole superconducting wigglers were manufactured in BINP on the base of NbTi superconductor. These wigglers are operating in various synchrotron radiation centers worldwide. High magnet design parameters were achieved by using the NbTi wire of high NbTi/Cu ratio, up to a factor of 2, and by grading current density in coils. So, further increase in the magnet...
A major problem of long duration manned missions in the deep space is the flow of high energy charged particles of solar (SPE) and galactic (GCR) origin. SPEs have short duration but can be extremely intense and can lead to acute, even lethal, effects. GCR flux is much less intense but is continuous, isotropic and more energetic; it increases the risk of carcinogenesis and can affect the...
The ITER TF Insert (TFI) coil is a 43 m long single-layer solenoid wound in the grooves of a stainless steel mandrel, using one of the Nb3Sn circular cable-in-conduit conductors adopted in the winding of the ITER TF coils and cooled with supercritical He in forced circulation at ~4.5 K. The TFI is the last in a series of ITER Insert Coils, all tested in the bore of the ITER Central Solenoid...
China Spallaion Neutron Source (CSNS) accelerators include a 80 MeV Linac, 1.6 GeV Rapid Cycling Synchrotron (RCS) and two beam transport lines. There are nearly 300 magnets for these accelerators, including 24 DC biased 25Hz AC dipole magnets, 48 DC biased 25Hz quadrupole magnets, 16 DC sextupole magnets, 34 AC correcting magnets and 23 injection & extraction magnets for the RCS and other DC...
In the electromagnetic tube expansion process, both electromagnetic force and workpiece deformation are axisymmetric. Hence, the forming performance of tube is better than that of sheet and then electromagnetic tube expansion is widely used in industry processing. However, the cylindrical coil is always applied to generate the electromagnetic force in electromagnetic tube expansion process at...
No-insulation (NI) high temperature superconductor (HTS) winding approach has been progressing as a promising technique to produce compact, reliable and robust magnets, and has demonstrated electromagnetic quench propagation and self-protecting nature. Comprehensive distributed network simulation models have been used to understand the mechanism of the self-protecting behavior in a qualitative...
An electromagnetic induction coilgun system accelerates a projectile in the axial direction which is a non-periodic moving. In addition, since the electromagnetic coilgun system converts the electrical energy to mechanical energy, the interactions between variables are very complex. Therefore, during a design process of the coilgun system, the design considerations are much more complicated...
The 3-GeV Rapid-Cycling Synchrotron (RCS) at the Japan Proton Accelerator Research Complex (J-PARC) has achieved the designed high power beam operation at 1 MW output. The study of an upgrade plan is then started to realize the 1.5-MW beam power. Regarding the radiation protection at the upgrade plan, a new injection system has been proposed to secure enough space for radiation shielding and...
The EU-funded EcoSwing project aims at demonstrating the world's first superconducting low-cost and lightweight wind turbine generator. This generator will use field coils based on second generation (2G) HTS wire which are manufactured using Pro-Line HTS tapes. During the development subscale test coils with different number of turns were produced and tested in liquid nitrogen as well as...
The ITER magnetic system includes 18 Toroidal Field (TF) Coils constructed using Nb3Sn cable-in-conduit superconductor. Each TF coil comprises a Winding Pack (WP) composed of 7 Double Pancake (DP) modules stacked together, impregnated and inserted into a stainless steel coil case. 10 TF coils are being produced in Europe, under the responsibility of Fusion for Energy (the European Domestic...
National Institutes for Quantum and Radiological Science and Technology, (QST), as Japan Domestic Agency in ITER, has responsibility to procure 9 ITER Toroidal Field (TF) coils. QST completed series production of the first seven double-pancakes (DP), all of which are for the first TF coil. The target tolerance of impregnated DP, 2 mm flatness, was achieved in all these DPs. These DPs were...
High Temperature Superconducting (HTS) generator for a large-scale wind power generation system draws much attention as a contemporary research item. Excitation systems in HTS generators, particularly brushless HTS exciters are a new challenge.This paper deals with the performance analysis of a 10 kW HTS wind power generator with brushless exciter and examines application possibility of the...
Qualification tests of the ITER Toroidal Field (TF) conductor joints have been carried out by testing short joint samples with test facilities in National Institute for Fusion Science. The joint sample consists of two short TF conductors with the length of 1,535 mm, which is restricted by the conductor test facility with 9 T split coils and 100 kA current leads. Each conductor has two joint...
Outside of the application field of (scientific) particle accelerators, in the applications area of semiconductor manufacturing equipment, demanding modules similar to accelerator magnets are developed and used: high field accuracy, high power levels (for high productivity), ultra-high vacuum regimes (EUV lithography), very limited outgassing and particle contamination (contamination of...
Sumitomo Electric has been developing conduction-cooled magnets using Bi2223 wire (DI-BSCCO). Due to high in-field critical current of the wire, the magnets can operate around 20 K. Consequently, iterative excitations and, central field of 10 T or R. T. bore of 300 mm in diameter have been achieved. With respect to reliability of the magnets, quench (thermal runaway) protection might be a...
Performance of the ITER toroidal field (TF) coil conductor has been measured in the SULTAN facility with 3.6 m straight configuration and joints at the sample top and bottom. However, this test condition includes large gradients of magnetic field along the conductor length caused by its only 0.45 m high field length. This condition, which is not present inside the ITER TF coils, could lead to...
The dynamic strain/stress characteristics and responds of a low temperature superconducting (LTS) sextupole magnet during excitation, pre and post spontaneous quench are investigated in the present work. The strains are measured by using a half-bridge circuit composed of a cryogenic strain gauge and dummy resistances. The strain gauges are directly embedded within the magnet structure, which...
The ITER Central Solenoid (CS) components are now being manufactured. This superconducting magnet will provide the magnetic flux swing required to induce up to 15 MA as plasma current. It includes six identical coils, called modules, stacked on top of each other to form a solenoid, enclosed inside a structure that has nine subsets, to provide vertical pre-compression and mechanical support....
A high precision superconducting levitation system for gravity measurement has been developed which used the levitation of a superconducting sphere by the magnetic field of two superconducting coils. The magnetic levitation is designed to provide independent adjustment of the levitating force and the force gradient. A GM cryocooler is employed to cooldown the system. This article reviews the...
Following a decision made at the ITER Council in November 2013, two types of In-Vessel Coils (IVCs), namely ELM Coils to mitigate Edge Localized Modes and VS Coils to provide Vertical Stabilization, have been incorporated in the ITER design. Strong coupling with the plasma is required so that the ELM and VS Coils can meet their performance requirements. Accordingly, the IVCs are in close...
A short stroke and large thrust axial magnetized tubular permanent magnet linear launcher (TPMLL) with non-ferromagnetic rings is presented in this paper. Its 3D finite element (FE) models are established for sensitivity analyses on some parameters, such as air gap thickness, permanent magnet thickness, permanent magnet width, stator yoke thickness and four types of permanent magnet material,...
We have developed A 9 T Cryocooler Cooled NbTi superconducting magnets. The system has a 60 mm cool bore and 0.1% homogeneity over a 10 mm diameter and 15mm length region. The cooling power of the cryocooler is 1.5 W at 4.2 K. The cool down time from room temperature to operating temperature is 15 hours. Three different diameter NbTi wire was used for winding the mangnet. The maximum...
Persistent current mode operation of a second generation (2G) high temperature superconducting (HTS) magnet is one of the bottleneck techniques for an HTS NMR or MRI applications. In order to realize the persistent current mode in the HTS magnet, the authors had proposed the concept of joint-less winding method with 2G HTS wide conductors and verified successfully that it could maintain...
The high pulsed magnetic field is an important scientific research tool for physics, material science, chemistry, medicine and so on. And the pulsed power supply plays an important role in generating pulsed magnetic field.Among all kinds of pulsed power supply,the capacitor bank power supply is most widely used for its simply structure and high reliability. And the resonant constant current...
Recently, brushless double-fed machines (BDFMs) have been widely developed due to the wide application prospects in electric power generation fields with variable speed, constant voltage and constant frequency performances and speed regulating systems using large capacity motor. The magnetic field generated by the two sets of windings, which are both located in the BDFM stator, indirectly...
Recently, flux-switching permanent magnet (FSPM) motors have been widely developed due to the merits of high power density, essentially sinusoidal back-EMF, and high fault-tolerance capability. However, FSPM motors usually suffer from disadvantages of high usage of rare-earth permanent magnet (PM) material and relatively low flux-weakening capability. So hybrid excitation flux-switching (HEFS)...
High field resistive magnets are traditionally build by stacking hundreds of so-called Bitter disks together to form a coil. Nowadays, these disks have strongly elongated cooling holes, arranged in a staggered pattern that improves the distributions of hoop stresses by the Lorentz force load on the disks. Near the outer diameter one finds larger holes, round or flattened, to accommodate a...
Tubular permanent magnet (TPM) motors have been applied to many direct drive systems such as electromagnetic suspension. Double-stator structure can take best use of the motor space and increase the slot area. The flux-modulation structure is based on magnetic gear effect, which makes full use of effective harmonic components of magnetic field. Thus, this structure can increase the force...
Among the various industries, the use of IPMSM in electric vehicle is increasing.In particular, in the case of an electric vehicle drive motor, the mechanical strength of the rotor is important because it operates in a high-speed operation region.Therefore, the double layer V-shaped magnet type IPMSM is more widely used in electric vehicles currently selling, because the double layer V-shaped...
Permanent magnet (PM) motors are field magnetic fluxes generated from PMs without external current input, which is advantageous in terms of power density and efficiency than non-PM motors. Due to these advantages, it has recently been applied in various fields such as electric vehicle and home appliances. The PM motor used mainly in the past was a surface mounted type in which PMs were...
We have been studying on a superconducting motor for highly efficient transportation equipment. Target motor of our study is a High Temperature Superconducting Induction/Synchronous Motor (HTS-ISM). Basic structure of the HTS-ISM is the same as that of so-called squirrel-cage induction motor, and HTS tapes are used in its rotor bars and end rings. Based on experiments and analysis, it has been...
The Magnet Section of the Paul Scherrer Institute (PSI) upgraded in 2017 its Hall probe magnet measurement bench with an in-house developed 3D Hall sensor of a distinctive type and of a high accuracy, named Hallcube. The first major magnetic field measurements at the upgraded bench were performed on a split coil magnet with iron housing. This magnet is routinely used on the low energy muons...
A 9-tape, 14 mm wide ReBCO Roebel cable was soldered onto a U-shaped holder. Ic was determined at 4.2 K with applied fields up to 12 T. At varying I/Ic, different heat pulses resulted in different quench behaviors. For a given sample, these different behaviors were used to construct a stability diagram. Stability diagrams were constructed for samples with different levels of insulation.
Compared to radial magnetization, Halbach permanent-magnet (PM) array inherits some attractive features: strong field intensity, self-shielding effect, near-sinusoidal airgap flux density distribution. Due to the difficulty in realizing continuous magnetization direction on single PM annulus, Halbach PM arrays are generally realized by discrete PM segments. In most cases, the magnetization...
The existing CSC-HVDC system must compensate for reactive power because of the using thyristors as power conversion switching elements. It is impossible to control active power and reactive power independently. The VSC-HVDC system is receiving attention for solving such a problem. In VSC-HVDC, the study of fault current interruption is necessary to improve the stability and reliability. In...
In general, Spoke type Permanent Magnet Synchronous Motor (PMSM) has intense air gap flux density due to its magnet arrangement. However, variation of machine performance is severe due to its design variables, such as air-gap length and magnet size. On the other hand, Surface Mounted PMSM (SPMSM) is less sensitive to change of variables that are mentioned above. In this study, we examine the...
High-speed permanent magnet (PM) machines are used in applications such as machining spindles, generation and storage of energy in vehicles, gas blowers, and other specialized applications. High-speed PM machines exhibit high efficiency, energy density, and dynamic capability. However, in these machines, overheating in rotors due to power loss can lead to problems because, unlike stators,...
This paper describes an analytical method to predict undesirable magnetic field inhomogeneity caused by manufacturing errors and evaluation of the permissible manufacturing tolerance for a high temperature superconductor (HTS) NMR magnet. Recently, HTS magnets have been actively studied for high-field nuclear magnetic resonance (NMR) (>1 GHz) magnet worldwide. Most high-field HTS magnet wound...
Electromagnetic field analyses of three-dimensional-shape coils wound with coated conductors are necessary for understanding their electromagnetic phenomena, calculating their ac losses, and evaluating their field uniformity and stability. We have been developing a series of models for the numerical electromagnetic field analyses using current vector potentials. In these models, because the...
Recently, the research and development of superconducting cables have been actively advanced all over the world. Particularly in RTRI, the research of superconducting cables for the railway electrification system (DC) is advancing. If the superconducting cables are used as a feeder of the railway system, the voltage decay could be significantly reduced. Therefore, DC High Temperature...
This paper presents a superconductivity fault current limiter(SFCL) DC interrupting system in wind power generation gird. SFCL DC interrupting system is comprised of SFCL and DC circuit breaker. When faults occurs, SFCL operates firstly to limit the maximum fault current and the residual fault current will be vanished by opening operation of dc circuit breaker secondly. To ensure the correct...
This paper presents a superconducting coil-type DC Fault Current Limiter(FCL). It has a combination structure of superconducting coils and DC circuit breaker in series. The superconducting coils operate as current limiting element. It was quenched when the fault is generated and limits the maximum fault current. Mechanical DC circuit breaker operates as interrupting element. It cut-offs the...
The coils of high field Nb3Sn magnets are submitted to large loads during assembly at ambient temperature and during operation at cold. This study addresses the characterization of the stress distribution on reacted and impregnated Nb3Sn Rutherford cables under transverse compression, at ambient temperature, in a similar configuration as seen during magnet assembly. We performed an...
A novel high temperature superconducting (HTS) flux pump device was built to charge second-generation (2G) HTS double pancake coils (DPC). This device generates a controllable ac travelling magnetic wave based on similar mechanism as a short-stator linear motor, while the wave has been dc-biased by dc windings on the magnetic circuit. A section of YBCO tape (superconducting stator) is placed...
The Laboratoire National des Champs Magnétiques Intenses (LNCMI) is a member of the European Magnetic Field Laboratory (EMFL). This is the French facility enabling researchers to perform experiments in the highest possible magnetic fields. The numerical modeling jointly developed with the Center of Modeling and Simulation of Strasbourg (Cemosis) plays an essential role in the understanding and...
In this paper, the transformer type superconducting fault current limiters (SFCLs) with common connection point between two secondary windings, which was similar structure to the previously suggested transformer type SFCL with two triggering levels, were proposed and their current limiting characteristics were compared. The suggested transformer type SFCLs consist of the primary winding and...
For the flux-coupling-type superconducting fault current limiter (SFCL) which is composed of coupling transformer (CT), superconducting component (SC) and controlled switch, it can be regarded as a typical application of magnet technology. As the flux-coupling-type SFCL offers many technical advantages, such as higher flexibility, better controllability and lower operation loss, this paper...
The 32 T project aims to combine a 15 T LTS magnet with two REBCO double pancake coils generating 17 T to create a 32 T user magnet for the MilliKelvin facility at the NHMFL. Both coil sets operate at 4.2 K using two separate power supplies. First, the construction of the REBCO coils and integration with the LTS magnet and cryostat is briefly described. Then, the cool down and performance...
We present construction and test results of Coils 2 and 3 of a 3-nested-coil 800-MHz (18.8 T) REBCO insert (H800) for the MIT 1.3-GHz LTS/HTS NMR magnet currently under construction. Each of the 3-nested H800 coils is a stack of no-insulation REBCO double-pancakes (DPs). The innermost 8.7-T Coil 1 (26 DPs) was completed in 2016; the middle 5.7-T Coil 2 (32 DPs) has been fully assembled and...
Permanent magnet (PM) machines are becoming popular as a key technology for applications such as home appliances, industrial tools, and electric vehicles. This is because of their high efficiency, high power density, and low maintenance costs. It is very important to consider the power losses in the initial design stage itself, because they determine the efficiency of the machine and have a...
We have investigated the relationship between local critical current distribution and global current capacity of multi-filamentary RE-123 coated conductor (CC). RE-123 CCs have critical issues on (1) spatial inhomogeneity in local critical current distribution which would become an origin of local burnout of a magnet coil and on (2) magnetization current which affects the spatial and temporal...
Toroidal field (TF) coils are superconductive magnets which create magnetic field to confine plasma in ITER vacuum vessel. In order to confirm TF coil’s functionality, magnetic field created by TF coil need to be evaluated and therefore, accurate measurement of current center line (CCL) is necessary. CCL of TF coil is defined as geometrical barycenter of all the conductors and accurate...
The current limiting and recovery characteristics of a trigger type superconducting fault current limiter (SFCL) using double quench, which consists of a power switch, two separated current limiting reactors and two superconducting (SC) elements, were analyzed. The suggested trigger type SFCL can perform two fault current limiting operations (single quench operation and double quench...
In this paper, the transformer type superconducting fault current limiter (SFCL) with additional secondary winding, which could limit the fault current through twice quench operations, was suggested. The suggested SFCL includes one primary winding, two non-isolated secondary windings wound on the same iron core, and two high-TC superconducting (HTSC) elements connected with each secondary...
Operating current of large-scale superconducting magnets needs to be enhanced up to several thousand to several tens thousand amps from the viewpoint of magnet protection in relation to the consumption of stored energy by an external resistor. On the other hand, superconducting magnets for MRI need the uniformity of produced magnetic field within ppm order in time and space. We proposed the...
Degradation of critical current in a high temperature superconducting (HTS) tape under bending conditions had been previously investigated. These investigations were focused on only either bending or torsion. A rotating flux pump is used to study the charging characteristics of HTS synchronous motor. In order to design the rotating flux pump connected in series, the elliptical winding applied...
Efficiency is an important index to evaluate the performance of an electric machine. Core loss takes a big part of the total losses of an electric machine. Amorphous alloy material (AAM) has much lower core loss than that of traditional silicon steel. An outer-rotor permanent magnet synchronous machine (OR-PMSM) with amorphous stator core is proposed in this paper, which exhibits higher...
The design and the characterization of high gradient permanent magnet (PM) quadrupoles, so-called”QUAPEVA” with variable strength are presented. The quadrupole structure is composed of a Halbach ring in the centre and four PM cylinders around. The central magnet provides a fixed gradient of 160 T/m. The four PM cylinders are used to achieve the gradient tuning range from 100 T/m to 200 T/m...
Saturated iron-core superconducting fault current limiter is a kind of promising device for short-circuit current limiting. During normal operation, large ampere-turns created with DC in the secondary superconducting HTS coil drive the core into saturation. This lowers impedance of the copper coil in the primary AC side near to that of an air - core coil. During a fault, a large fault current...
This paper presents design and implementation of ferromagnetic shims for a conduction-cooled 3-T 100 mm winding diameter no-insulation (NI) all-REBCO magnet. The initial magnetic field profile was measured by an in-house 3-D field mapper with an NMR magnetometer, from which harmonic coefficients up to 3 order are derived. A ferromagnetic shim design code was developed, which includes an...
Four normal conducting 2.4 tesla “superbend” magnets will be installed in the phase-II beamline project at Shanghai Synchrotron Radiation Facility(SSRF), replacing the current 1.27 T ones. We present the design and the magnetic measurement results of the first prototype magnet in this paper. Also described is a newly-developed field shimming method which has shown its efficiency and simplicity...
The flux-coupling type superconducting fault current limiter (FC-SFCL) is suggested to suppress the short-circuit current in the dc line of VSC-HVDC system. The FC-SFCL could generate larger inductance and smaller resistance at the beginning of current limiting process, but show smaller reactance and very large resistance at the end. One FC-SFCL module with two branches is designed and tested....
Superconducting fault current limiters (SFCLs) are considered as one of the most technical potentials to limit fault current levels, for that they can suppress fault currents without adding impedance to the circuit during normal operation. In this paper, a small-scale test prototype of the flux-coupling type SFCL (FC-SFCL) is designed and fabricated, and a series of experimental tests are...
Recently super high speed magnetic levitation MAGLEV using high temperature superconducting (HTS) magnet has been expected as next generation transportation since superconducting magnet can keep mighty levitation force. The superconducting magnet at MAGLEV train should be continually charged with high power in order to keep stronger and stable levitation force. Practically, since conventional...
Flux reversal machines (FRMs) have a stator with permanent magnets (PMs) mounted on the surface each teeth and a reluctance rotor. As the flux field excited by the PMs is almost constant, the magnitude and phase of the stator current are often adjusted to realize the flux-weakening operation, but it usually sacrifices the output torque. As we know, HTS wound field machines can easily adjust...
Recently, various types of electric motor are applied to vehicle traction field because of strengthened environmental law. In general, Interior Permanent Magnet Synchronous Motor(IPMSM) has high power density and efficiency due to reluctance torque by adopting permanent magnet. By these advantages, IPMSM is widely used in Electric Vehicle(EV) traction motor.In case of EV traction motor,...
At J-PARC Main Ring (MR), there have been various investigation carried out at the moment aiming at the beam operation of MW order. As one of the investigations, a study of the Rapid-Cycling Synchrotron (RCS) magnets was implemented. Increase of the extraction energy of RCS was needed to reduce beam loss, as beam loss in the MR injection region was large under influence of the space charge...
AC electric field distribution in composite insulation materials is mainly determined by their permittivity. However, DC electric field distribution highly depends on the electrical conductivity of the insulating materials, and this electrical conductivity exponentially increases with externally applied electric field in cryogenic environment. Therefore, we should not only obtain the accurate...
Since the accomplishment of the pulsed magnetic field facility at the Wuhan National High Magnetic Field Center, a few types of pulsed magnets, such as the 40 T helical magnet, 65 T monolithic-coil magnet and 90 T dual-coil magnet, have been developed and are now in operation for scientific research. As the workhorse, the 65 T user magnets show excellent cooling performance and long service...
We are starting the development of a persistent 400 MHz (9.39 T) LTS/REBCO NMR magnet as a first step towards a 1.3 GHz (30.5 T) LTS/HTS NMR. The 400 MHz magnet consists of a layer-wound REBCO innermost coil and an LTS outer coil which are operated in individual persistent circuits. The system requires the following technical developments; (a) a REBCO-REBCO superconducting joint, located above...
ITER project has been running in decades and has started after complications. While it is now under construction, design activity for new fusion device called “DEMO” has already taken place, in which the superconducting magnet system will be much larger than that of ITER. In the present project, the magnets are made of Nb3Sn superconducting material, hence heat treatment is needed to generate...
The unique magnets for compact NMR relaxometry device consisted of the stacked high temperature superconducting (HTS) bulk annuli trapped by a field cooling (FC) method are suggested and studied. The magnetically charged HTS bulk magnet for NMR relaxometry device is cooled by liquid nitrogen and no more need a power supply. The strength and homogeneity of the magnetic field required for the...
In the context of the HL-LHC project, a NbTi double aperture quadrupole magnet called MQYY is being developed. This 90 mm aperture quadrupole magnet has a magnetic length of 3.67 m and an operating gradient of 120 T/m at 1.9 K. Its development is done along two parallel paths: 1) the design, fabrication and test of a short model, 2) the design and fabrication of two full scale prototypes in...
Next generation electric power systems require higher capacity, efficiency, and stability to meet the demands of increasingly complicated grid systems. High-temperature superconductors (HTS) provide unique solutions to stringent operating requirements, including the ability to protect electric power apparatus and systems from large currents that can develop during a fault. The extensive...
Karlsruhe Institute of Technology (KIT) developed the HTS Cross Conductor (CroCo), a round twisted stacked REBCO strand with outer Cu envelope, optimized for high current density and easy long length fabrication. First generation of HTS CroCos were built from 6 mm and 4 mm wide REBCO tapes with critical currents Ic ~ 3 kA (77 K / s.f.) and Ic > 8 kA (4.2 K, 12 T). Due to the continuously...
This paper deals with the simulation of the JT-60SA tokamak toroidal field coils test facility in CEA Saclay. To have a better understanding of the thermohydraulic behavior of the coils, a model of the cold test facility cryodistribution coupled to a model of the coils has been developed. Each of the 12 Pancakes is modelled by a 1-D thermohydraulic tube of Simcryogenics code representing the...
In recent year, the demand for high speed permanent magnet(HSPM) motor is increasing in various fields due to its high efficiency and high power density. The research and application of high speed permanent magnet motor meets the needs of economic development of energy conservation and emission reduction. However, there are some studies have found that the rotor heating is very serious, which...
Superconducting devices have emerged in many applications during the last few decades. They offer many advantages including high efficiency, compact size, and superior performance. However, the main drawback of these devices is the high cost. An option to reduce the high cost and improve the cost-benefit ratio is to integrate two functions into one device. This paper presents the...
To distribute the mechanical load and to reduce the driving voltages, ultra-high field pulsed magnets are usually designed as a group of nested, concentric coils driven by separated power sources. Since the magnet operated in a fast transient mode, there will be strong and complicated electromagnetic and mechanical couplings between the component coils. The high eddy currents generated in the...
Sections of the superconducting magnets of SIS100 particle accelerator (under construction at GSI, Darmstadt) are going to be connected with by-pass lines used to transfer electric current and liquid helium. Each by-pass line will contain four pairs of Nuclotron-type superconducting cables (bus-bars) used to supply the different types of magnets with electric current. Since the accelerator is...
There exist a number of experiments/applications where the second dimension of the bore of Bitter magnets is not fully utilized and thus not really needed. Using an analytical solution for elliptical bore coils, as well as finite-element analysis for elliptical and racetrack bore coils, we show that reducing one of the dimensions of the bore can lead to a considerable decrease in consumed...
The central solenoid (CS) of JT-60SA is composed of the four electrically independent modules, and 6 octa-pancake coils and a quad-pancake coil are assembled vertically in one module. The CS module is supplied with current through the room temperature busbar and current feeder of the superconductor. The withstand voltage for the insulation between the conductors is one of the most important...
High-temperature superconducting (HTS) synchronous motors conventionally require current leads to inject the large DC currents into HTS field coils. However heat losses are generated on these current leads due to mechanical connection between the HTS field coils and power supply. For that reason, rotary HTS flux pump is used to remove the physical connection. However, HTS flux pump has spatial...
Cable-in-conduit (CIC) conductors made of Nb3Sn wires have been developed for use in large high-field magnets. A "wind, react and transfer" method has been established to avoid the degradation by excess strain after reaction of Nb3Sn and to adopt organic insulator. However, the "react and wind" method is preferred for a helical coil for a helical fusion reactor, because the "transfer" process...
High temperature superconducting (HTS) conductors are expected to improve small sized high field magnets. However, the mechanical stresses lower the critical current properties of the HTS tapes. The objective of this work is to clarify the relationship between the critical current properties and the total tensile stresses caused by the winding tension during the coil winding process and the...
High Voltage Direct Current (HVDC) transmission systems using Voltage-Source Converters (VSC) are widely recognized as having significant potential for long distance high power delivery, particularly for offshore wind farm connections. The US Navy has also proposed a Medium Voltage DC (MVDC) distribution architecture for the all-electric shipboard power systems. NASA is also evaluating...
Enhancement of the repetition rate of high field pulsed magnets is significant for the efficiency of the experiments under pulsed high magnetic field. Adding a liquid nitrogen cooling gap of 3-5 mm has been proven to be a feasible method to increase the cooling efficiency and improves the repetition rate of pulsed magnets. Study indicated that the cooling efficiency increased with the number...
The Beam Test Facility (BTF) is part of the DAΦNE accelerators system of INFN Frascati National Laboratory (LNF). It is a transfer-line optimized for selection, attenuation and manipulation of electrons and positrons extracted from the DAΦNE LINAC. An upgrade of the line is scheduled by the end of 2018 in order to reach a beam energy of 920 MeV (with respect to the actual 750 MeV) and a new...
This paper deals with a design concept of a multi-pole electro-magnet using parallel iron-core structure. The electro-magnets can be used in many kinds of magnetic study such as magnetic susceptibility, hall effect research, magneto-optical effect, and hysteresis measurement. In electro-magnets, generally, only a single probe can be applied at a time due to the single pole structure, and it is...
At the Japan Proton Accelerator Research Complex, a new experimental facility called the Transmutation Experimental Facility (TEF) is planned for the Accelerator-Driven System. The TEF facility will use the 400 MeV proton beam from the LINAC, which requires introducing a beam switching system at a Beam Transport from the LINAC to the 3GeV Rapid Cycling Synchrotron (RCS). A pulse bending magnet...
Quadrupole magnets are used extensively in particle accelerators, synchrotrons, and storage rings all over the world. Excellent field quality in these quadrupole magnets is needed at these facilities, which requires machining the magnet parts to high precision with conventional magnet designs. An eight-piece quadrupole design and assembly method are developed that produce the desired magnetic...
A finite element method was developed to investigate the strain distribution of REBCO coated conductors under bending conditions relevant to high-field accelerator magnets. Due to their high current and high field capabilities, REBCO tapes are promising conductors for high field magnet applications. During magnet fabrication, REBCO tapes bend around a former. Because of the asymmetric...
Flux pumps can inject high dc currents into superconducting coils, without requiring electrical connections between the cryogenic superconducting circuit and the room-temperature environment, thus significantly lowering the heat load on the cryogenic cooling system. Here we study a dynamo-type flux pump employing 2G ReBCO coated conductor wire at 77 K with multiple spinning Nd-Fe-B magnets and...
A multi-scale mechanical model of Rutherford type, low temperature superconducting cable is discussed in this paper.
First, the numerical approach for the mechanical analysis of the cable using bi-metallic description of the strands is presented. The process of the three-dimensional geometrical reconstruction of the cable during operation, up to the scale of the strand, is described. The...
In this paper we present design, construction, and preliminary test results of a proof-of-concept (POC) prototype, high-temperature superconductor (HTS) shim coils energized, for the first time ever, by a flux pump. For high-resolution NMR spectroscopy the spatial magnetic field must be uniform to within <0.1 ppm over a given region of interest (ROI). Field shimming is indispensable for...
Dynamo-type flux pumps provide a contact-free method of energizing currents in superconducting coils. Since a detailed predictive theory for these devices does not yet exist, the effect of design parameters must be studied empirically. In this work we investigate the performance of an experimental flux pump employing a high-temperature superconductor stator located upon a ring shaped iron...
Abstract- The stator-magnet moving-iron transversal-flux linear oscillatory machine (SMTLOM) offers the merits of high reliability and robustness, high material utilization ratio, low fabrication difficulty and cost and so on. However, due to its iron mover, the weight of moving structure is relatively higher than that of moving-magnet linear oscillatory machine (MLOM). Consequently, a rather...
The Canted-Cosine-Theta (CCT) is a design option for the next generation of high field superconducting dipoles which is being pursued within US Magnet Development Program. This paper presents new modeling techniques developed for design and analysis of this type of magnet. For mechanical modeling in ANSYS, three approaches with increasing accuracy will be compared: 2D symmetry models, 3D...
Energy harvesting refers to a process that derives a small amount of power from external energy sources. The energy sources of harvesters can be easily obtained anywhere from vibration, wind power and wave power. In this study, we will focus on vibration, one of the typical energy sources that can be easily changed into an electromotive force (EMF), as our study subject. Mechanical vibration...
Large hoop stress causes the deterioration of the transport properties of the winding. Therefore, high electromagnetic force tolerance is required for structure of the winding, and at the same time, it is necessary to limit the current density so as not to deteriorate the superconducting characteristic. As this countermeasure, a high strength pancake coil structure called “Yoroi-coil” (Y-based...
In order to developing the nuclear magnetic resonance (NMR) superconducting magnet and other applications, a series of high field magnet manufacture technologies are researching in our institute, IEE CAS. The Nb3Sn superconductor is indispensable for the 500 MHz and above NMR magnet. In this paper, a dynamic vacuum pressure impregnation (VPI) process of Nb3Sn coil on the basis of Darcy’s law...
MgB2 superconductors are recognized as one of the promising superconducting wires for utilizations in a current MRI magnet. However, a practical consideration remains that the critical current density and critical magnetic field of the MgB2 wire strongly depend on the stress applied by bending the reacted MgB2 wire. Therefore, the investigation of the electrical properties of the reacted MgB2...
The Brushless DC (BLDC) motor is widely applied in various fields, such as tractions, communication devices, and home appliances, by virtue of its high-power density, wide operating range, high efficiency and simple drive system. Two kinds of BLDC motors, “Y-connection, 2-phase excitation system” and “∆-connection, 3-phase excitation system”, have many differences. A major difference is the...
The LCLS-II at SLAC utilizes an arrangement of kickers and septa magnets to direct the electron beams from the normal and superconducting linacs to the soft and hard x-ray undulator beamlines. A consequence of the performance requirement for kicker pulse rates as high as 1 MHz. is the beam separation at the face of the septum is limited to 15mm. This imposes physical constraints on the...
ENEA, in collaboration with CRIOTEC Impianti S.r.l. and TRATOS Cavi S.p.A. (the three associated members of the Italian Consortium for Applied Superconductivity, ICAS) has manufactured approximately 100 km of Cable-in-Conduit-Conductors (CICCs) in the last decade, mainly for fusion tokamak, but also for different applications such as magnets for testing facilities. This production includes a...
Our project research group has proposed a High Temperature Superconducting Induction Synchronous Motor (HTS-ISM) for the next generation transportation equipment, such as ships, trains, buses, and automobiles. The basic structure of the proposed HTS-ISM is as same as that of the traditional squirrel-cage induction motor. The difference is replacing the rotor (secondary) windings to the HTS...
With the development of DC power supply systems, breaking capacity of circuit breakers has been increasingly unable to meet the growing requirements for DC system short-circuit current level. To ensure the safety of the systems, a fault current limiter must be used in series with circuit breakers. The properties of superconducting fault current limiters such as fast reaction rate, simple...
Magnetic measurements of the NICA booster superconducting magnets NICA is a new accelerator collider complex under construction at the Joint Institute for Nuclear Research in Dubna, Russia. The facility includes a new superconducting booster synchrotron consists of 40 dipole and 48 quadrupole superconducting magnets. Booster magnets are under series production, assembling and testing at new...
The future heavy ion synchrotron SIS100 will have series of two dc magnetic septa for the injection and three dc septa on the extraction line. The extraction line will allow for two different extraction schemes for vertical fast extraction and initially horizontal slow extraction. The latter requires among other components two additional Lambertson-type septa. The design of the magnets had to...
The amplitude of magnetic permeability and the electromagnetic losses of silicon steel sheet are important to design all kinds of motors. It is necessary to analyze magnetic permeability and electromagnetic losses before designing efficient motors. Different magnetic hysteresis loops are measured using AMH-1M-S dynamic testing system from Laboratorio Elettrofisico Walker LDJ Scientific, Italy...
Superconducting bulk materials have high trapped magnetic field ability at a temperature lower than the critical temperature. Since superconducting bulk materials are subjected to electromagnetic force during magnetization process, improvements of the mechanical properties are indispensable for the development of high performance bulk materials. However, the mechanical properties of...
Recently, the Rotary flux-pump using HTS tape has been researched to apply for superconducting applications. In this paper, we studied the charging characteristics of the field coil of the HTS synchronous motor that field coil is charged by Rotary HTS flux-pump. The two advantages can be obtained by using Rotary HTS flux-pump to the synchronous motor. 1) The high thermal efficiency 2) simple...
Bearingless synchronous reluctance motors (BSRMs) have received more and more attention in recent years. Besides some general advantages of non-friction, high critical speed and non-lubrication of bearingless motors (BMs), the BSRM have some additional characteristics of simple structure, low loss and low temperature rising. Therefore, BSRMs have wide application prospect in some special...
Recently electric tools have been widely used in industrial applications and human livings, and will be increased very greatly in near future. Till now, most electric tools have been driven by concatenated induction machine, which suffers big volume, low torque density, low efficiency, poor reliability, etc. Fortunately, single-phase doubly salient permanent magnet machine (SP-DSPMM) has been...
Traditional heteropolar radial hybrid magnetic bearing (HRHMB) with eight poles has been widely applied in high-speed applications, such as flywheel energy storage system (FESS), because of its simple structure, low power loss, and high critical speed. However, this topology suffers large displacement stiffness, magnetic coupling, and non-negligible rotor iron loss. To overcome these...
RE-Ba-Cu-O (RE: rare earth element or Y) bulk superconductors have promising potential to be used as a strong trapped field magnet (TFM), which ever can trap a field of over 17 T on a Gd-Ba-Cu-O disc bulk reinforced with the shrink-fit steel. Ring-shaped bulk cylinders with a concentric hole are also considered in practical applications, such as nuclear magnetic resonance (NMR) spectrometer...
High temperature superconducting (HTS) device is a new application of superconducting technology in power system. In real utility, HTS device expose to environment where there exists many problems, such as crushing stress, bending stress, background magnetic field and so on. To ensure the safety of the HTS device, it is necessary to study the stability behaviors of HTS tapes. In addition,...
The wireless power transfer (WPT) technology based on strongly resonance coupled method realizes large power charging without any wires through the air. Recently, the WPT systems have started to be applied to the wireless charging for unmanned underwater vehicles (UUVs), power is the critical factor that often determines mission lifetime. Unlike many terrestrial vehicles, where batteries can...
A 5 T low temperature superconducting magnet is designed and will be fabricated for EMPS (Electro-Magnetic Property measurement System) whose sample space is 50 mm in diameter. Since the sample space is twice larger than that of the conventional property measurement systems, it will be possible to measure the electro-magnetic properties of several samples at a time, therefore measurement time...
The HTS dynamo is a type of superconducting flux pump which employs a series of permanent magnets mounted upon a mechanical rotor. Interaction between flux from the rotor magnets and a coated conductor stator wire gives rise to a time-averaged DC emf, which is imposed across a series-connected superconducting coil. By employing a pair of soft ferromagnetic yokes, the device can be arranged...
In the past two decades, a bearingless synchronous reluctance motor (BSynRM) was proposed and developed. Besides the advantages of the traditional bearingless motors, the BSynRMs have the advantages of simple structure, low cost, low losses and can realize high speed operation using flux weakening control. Therefore, the BSynRMs have broad application prospects in vacuum, high speed, high...
The SIS-100 is a charge particle accelerator developed as a part of the challenging international project Facility for Anti-proton and Ion Research (FAIR) taking place in Darmstadt, Germany. The ion optics of the SIS-100 accelerator includes superconducting and normal conducting quadrupole magnets. To fulfill the requirements of the field quality in the magnet aperture it is necessary to find...
Superconducting fault current limiter (SFCL) is an efficient way to solve the short-circuit problems in modern power system. A novel Flux-coupling type SFCL (FC-SFCL) based on disconnecting coupling windings for current-limiting has been proposed.For its low steady impedance at normal state and high limiting one after fault, FC-SFCL is considered as a potential scheme to limit short-current....
By using the powder metallurgy technology and magnetic isotropy characteristic of the soft magnetic composite (SMC) material, various kinds of permanent magnet (PM) machine can be designed and fabricated easily. However, if the torque density of the PM machine with SMC cores is much lower than that with the silicon steels, if it is designed with the traditional structures and methods. In the...
CEA has the responsibility of the design studies for the superferric 1.6 T dipole magnets of the Superconducting FRagment Separator (SuperFRS) which is part of the Facility for Antiproton and Ion Research (FAIR) in Darmstadt, Germany. After completing the study for the 21 superferric SuperFRS standard dipole magnets, CEA is currently analysing conceptual solutions for the 3 superferric...
The CERN LHC Injectors Upgrade (LIU) seeks to reliably deliver the beams required for the High- Luminosity LHC (HL-LHC). As part of this, the Proton Synchrotron Booster (PSB) will be upgraded from 1.4 GeV to 2 GeV and will accelerate higher intensity beams. Along the transfer lines between the PSB and the Proton Synchrotron (PS) there are several D.C. operated quadrupoles which are unable to...
Construction of the High Luminosity Large Hadron Collider (HL-LHC) is being planned for an increase of luminosity in order for the further exploration of the physics beyond the Standard Model. Under this program, a series of final focusing magnets, including a beam separation dipole (D1), has to be upgraded, and we, KEK, are responsible for development of the new D1 magnet. This magnet is...
In the framework of the EUROfusion DEMO project, studies are conducted in several European institutions for designing the tokamak magnet systems. In order to generate the high magnetic fields required for the plasma confinement and control, the reactor should be equipped with superconducting magnets, the reference design being based on Cable-In-Conduit Conductors (CICC) cooled at cryogenic...
The CFETR, “China Fusion Engineering Test Reactor”, is a new tokamak device. Its magnet system includes the Toroidal Field (TF), Central Solenoid (CS) and Poloidal Field (PF) coils. The main goal of this project is to build a fusion engineering tokamak reactor with fusion power of 50-200 MW and self-sufficiency by blanket. The maximum field of CS and TF will get around 15 T, which is much...
The novel coil assisted reluctance motor is a kind of high torque DC motor combined with traditional permanent magnet brushless DC motor and switched reluctance motor. The motor with double sets of armature windings and the central coil (field winding) which is installed between two-stator-rotor by axial excitation has a 9\6 symmetric double salient pole structure. Based on the special...
Terfenol-D has giant energy density (25kJ/m3) and relatively high thermal conductivity (13.5w/ (m•k) at 20°C). It is the core component of giant magnetostrictive transducer (GMT) which has been widely used in the field of ultra-precision machining and precision fluid control technology. However, when GMT operates under 6000Hz high frequency magnetic field, hysteresis loss, eddy current loss...
For the purpose of contactlessly measuring a critical current density in a high-temperature superconducting (HTS) film, the contactless methods such as the inductive method, the hall probe method, and permanent magnet method have been developed. These methods are applied to the distribution measurement of the critical current density for the case with large-area samples such as an HTS wire or...
Inductive pulsed power supplies attract attention from lots of research institutions and scholars since the energy density of inductors is approximately one order of magnitude higher than that of capacitors. Institute for Advanced Technology (IAT) proposed an inductive pulsed power topology named Slow Transfer of Energy through Capacitive Hybrid (STRETCH) meat grinder. In recent years, HTS...
The first European superconducting Winding Pack (WP) and the first set of Coil Cases (TFCC) for ITER are going to be delivered in 2017. The TFCC are steel structures which provide structural integrity to the WP, contribute to neutron shielding capacity, provide support to operating forces and offer interface connections with the rest of ITER machine. The TFCC assembly is formed by four main...
Nuclear magnetic resonance (NMR) spectrometer with high resolution using superconducting coils is a powerful apparatus to analyze complex molecular structure or to develop new drugs. Recently, a compact and cryogen-free NMR spectrometer with a medium resolution of 200 MHz (4.7 T) has been developed using annular REBaCuO superconducting bulks, in which the NMR spectra of ethanol with a full...
The THOMX facility is a compact ring source based on Compton Back Scattering (CBS), under construction at LAL in Orsay (France). Due to high constraints as its compactness (18 meters long storage ring), the low electron energies (ranging from 50 to 70 MeV), the non-linear beam dynamics, the limited beam storage (60ns per turn), THOMX accelerator has to face many technical challenges. One of...
An all permanent High Field Superbend Dipole is proposed for the new Sirius optics can now provide hard X-rays in a critical energy of 19 keV. In the new design, the superbend has a much stronger magnetic field with a 3.2 T peak and it is composed of two low field parts designed with a transverse gradient on each side of the high field pole. The full magnet is joined into a single permanent...
ThomX is a Compton source project in the range of the hard X rays (40 / 90 keV). The machine is composed of an injector Linac and a storage ring where an electron bunch collides with a laser pulse accumulated in a Fabry-Perot resonator.
The injection and extraction of the beam in the storage ring is managed by an UHV eddy current septum magnet. This eddy current septum magnet has to generate a...
The 2G coated conductor (CC) tapes exhibit greater potential in magnet and coil applications because of their high critical current density, Jc and good mechanical properties along longitudinal direction. Differences in fabrication processes, architecture, and layer materials in REBCO CC tapes produce different mechanical and electromechanical behaviors under magnetic field B, temperature T,...
ABSTRACT: The mechanical characteristics and behaviors of two superconducting magnets with different low temperature superconducting materials and configurations during excitation and quench training processes are investigated experimentally and numerically in the present work. One is a racetrack magnet made of NbTi/Cu with the maximum magnetic field of 4 T. Another is hybrid superconducting...
The superconducting property of Nb3Sn strands is very sensitive to strain. The transverse electromagnetic loading has been considered as a major origin of the degradation of Nb3Sn cable-in-conduit conductor (CICC) due to the periodic local bending. The degradation of each strand due to this bending should be evaluated to calculate the performance of a CICC. Thus, an analytical model considered...
The quench protection system of the non-planar coils of the Wendelstein 7-X stellarator was laid out over fifteen years ago. At that time, the assessment of the hot spot temperature by a basic adiabatic model was done using design values for material and operation parameters. After the operating experience in 2016, the hot spot temperature is re-assessed with the thermal-hydraulic program...
General Atomics (GA) is fabricating the ITER Central Solenoid Modules (CSM). The production contract also includes the design and qualification of tooling necessary for fabrication and full current cold testing. Each of the seven
modules will undergo final testing at GA to verify performance. GA is currently commissioning the Final Test Facility at the CSM Manufacturing site in Poway,...
The SwissFEL project at the Paul Scherrer Institute (PSI) has entered its final phase with most of the magnets having been measured and installed. The beam dump dipole in the Injector-Linac 1 section of the SwissFEL facility serves not only to dump the electron beam but also acts as a spectrometer. Optimisation of the magnet pole profiles and pole ends, in order to achieve a good field region...
The ITER Poloidal Field (PF) magnet system is composed of six circular coils, consisting of winding packs (WP) made up from a stack of Double Pancakes (DP) wound of NbTi cable-in-conduit superconductor. The largest coil has a diameter of 24 meters, the heaviest weighs 400 tons, and they are designed to produce a total magnetic energy of 4 Giga Joules at a maximum magnetic field of 6 Tesla for...
No-insulation (NI) coil made of 2G HTS tape has many advantages over insulated coil that it has higher engineering current density and self-protection characteristic. While there are few researches of NI coil in AC power application due the charging/discharging delay of NI coil. In this paper, we apply NI coil into inductive superconducting fault current limiter (iSFCL) as the secondary...
A new proton therapy scanning system for the treatment of can-cer has been accomplished at the Shanghai Institute of Applied Physics (SINAP/China). It is mainly comprised of two separate dipole magnets, each controlling horizontal and vertical direc-tions scanning independently. According to the design require-ments, we have confirmed the dimensions of the magnets and op-timized the local and...
Current leads of a superconducting magnet are one of the largest heat source to the superconducting magnet cryo-system. A flux pump is one possible way to remove the current leads by replacing conductive connection to magnetic coupling. However, the heat loss of the flux pump should be analyzed in order to apply to conduction cooled magnet because of little temperature margin in conduction...
This paper describes an innovative synthesis rotor geometry technique of permanent magnet assisted synchronous reluctance motor (PMAREL) with different flux barrier rotor shapes. The two symmetric rotor optimizations are examined and synthesis to establish the best asymmetric rotor geometry. The research results point out that the synthesis asymmetric rotor geometry is a more satisfying...
The Laboratoire National des Champs Magnétiques Intenses (LNCMI) is a member of the European Magnetic Field Laboratory (EMFL). This is the French facility enabling researchers to perform experiments in the highest possible magnetic fields. The numerical modeling jointly developed with the Center of Modeling and Simulation of Strasbourg (Cemosis) plays an essential role in the understanding and...
Flux pumped ultra-high field magnets have the potential to produce fields which surpass the nearly 20 year old record of 45 T in a DC field Bitter magnet in a relatively cost effective manner. These higher fields will undoubtedly require superconducting cables capable of carrying thousands of amps and the means to deliver those very high currents. Current leads could be used but at currents...
We have conducted research and development on a high-temperature superconducting motor, which has been expected as a next generation transportation equipment. Our target motor is so-called high-temperature superconducting induction/synchronous motor (HTS-ISM). The HTS-ISM has the similar structure as a squirrel cage induction motor, but replaces the winding with a HTS wire. Basically, by...
In order to improve the fault tolerant (FT) capability suitable for high reliability operation, FT teeth and concentrated windings are designed in two FT flux-switching permanent-magnet machines, namely 10/18-pole and 10/19-pole. However, they still suffer from vibration and noise due to radial force fluctuation. This paper compares the vibration characteristic of both machines. Because odd...
Thinner substrate ReBCO tapes, nowadays produced by SuperPower, make it possible to wind thin CORC based ReBCO wires of 3 to 4 mm diameter. The reduction of the tape’s substrate thickness from 100 via 50 to 30 micron leads to a significantly reduced minimum bending radius of ReBCO tapes. The 30 micron substrate tapes can now also be manufactured with a width of only 2 mm. Thinner substrates...
Magnetization and AC loss measurements were performed on cables made from HTS coated conductors. Coated conductor-based CORC, Twist stack, and Roebel Style cables were measured and were compared. In a first set of runs, magnetization was measured out to 1.4 T at 4 K, and was compared for the various cable options with reference to the field at injection for particle accelerators. Additionally,...
To achieve the required current capacity, superconducting cables are composed of numerous HTS tapes. In particular for application in fusion, those conductors have to operate in alternating current and magnetic fields, leading to AC loss and current redistribution. Besides the dimensions and geometry of the composed cable, an important parameter for the mentioned phenomena is the contact...
The fragment separator of the HIAF (High Intensity Heavy-ion Accelerator Facility) project called HFRS requires quadrupoles with high gradients( 11.4 T/m) and large bores (gap width of 160 mm). The iron dominated magnets with superconducting coils have been widely used in the similar facilities such as A1900, BigRIPS, Super-FRS and RISP with the advantages of low request for coils...
We have succeeded in evaluating local critical current (Ic) and n-indices in a long-length GdBCO coated conductor as a function of longitudinal coordinate with a spatial resolution of 1 mm under external magnetic fields up to 5 T at both temperatures of 77 K and 65 K. While the sample was carried in reel-to-reel manner in a liquid nitrogen bath with an external magnetic field, we measured...
The large magnetization caused by shielding current in coated conductors can deteriorate the field qualities of magnets. One of the counter measures of this large magnetization is the striation of a coated conductor to divide its superconductor layer into multifilaments. A striated coated conductor was fabricated by Furukawa Electric Co., Ltd. and SuperPower Inc. The superconductor layer of a...
High charge state ECR ion source has become an indispensable machine in heavy ion associated physics research. It has got remarkable advancement in the last several decades. Modern heavy ion accelerator technology needs very intense highly charged heavy ion beams, therefore very high performance ECR ion sources are needed by many large scale heavy ion facilities. So called 3rd generation ECR...
A superconducting magnet has been developed for SECRAL II ion source at IMP. The design of this magnet is based on SECRAL, with sextupole coils external to the axial solenoids to reduce Lorentz force between sextupole coil’s end and solenoids. The magnet consists of a set of sextupole coils and three solenoids to generate a confinement magnetic field. All the coils use a NbTi conductor and are...
State of the art high field and ultra-high filed magnets demand HTS conductors with ever-increasing critical current. SuperOx is conducting an industrial R&D effort, in order to improve the performance of 2G HTS wire in magnetic field by introducing perovskite artificial pinning centres into the HTS film matrix. This paper will report the results of critical current measurements of BaZrO3 and...
In order to use a REBCO coil with conduction cooling configuration, AC loss of the coil should be quantitatively predicted and designed under the operating conditions. REBCO-coated conductor is a tape shape and is suited to be composed of a stack of single pancake coils for generating high magnetic field. And various research groups measured and evaluated the ac loss of the REBCO tape;...
THEVA Pro-Line coated conductors based on ISD-MgO buffer layers and e-beam evaporation are available today in large length and critical current above 500 A/cm (77 K, s.f.) as it is necessary for magnet applications. An overview will be given on recent progress of the performance and length of these kind of coated conductors. The performance in magnetic fields at medium temperatures in the...
NICA is an accelerator collider complex under construction at the Joint Institute for Nuclear Research in Dubna. The facility is aimed at providing collider experiments with heavy ions up to Gold in the center of mass energy from 4 to 11 GeV/u and an average luminosity up to 1∙10^27 cm-2 s-1 for Au^79+. The collisions of polarized deuterons are also foreseen. The facility includes two injector...
This paper presents a 8T solenoid used to focus and steer the heavy ion beams of the Facility for Rare Isotope driver linac at Michigan State University. It includes a main focusing solenoid, two bucking coils, two pair of horizontal and vertical correctors. The magnet is assembled with an entire length of 516 mm, including the helium vessel, ICR vacuum flanges and also the VCR for the helium...
The effects of electron beam (EB) irradiation on the defect formation and critical properties of YBCO thin films were investigated. The YBCO superconducting films were irradiated using an EB accelerator with an energy of 0.2 MeV and a dose of E15-E16 e/cm2. The value of the critical temperature (Tc) decreased and the superconducting transition broadened by the EB irradiation. In spite of the...
Dissipation of energy in a superconducting coil generating magnetic field that varies in time could be evaluated locally as the product of electrical field and current density. The effect of electric field exerting force and accelerating the electric charge carriers that transport the current is commonly incorporated into AC loss calculation by inserting a realistic current-voltage dependence...
WST has been engaged in LTS and HTS since its foundation. WST has finished 210 ton of Nb3Sn and NbTi superconducting strands for ITER. The experience of the ITER wire production brought great improvement to high-performance LTS as well as HTS for fusion, MRI and accelerators.
Half a century of development activities on superconductors, such as NbTi, bronze-processed Nb3Sn and REBCO, at Furukawa Electric Group will be presented.
Plans for the future will be presented as well.
For over 40 years metallic superconductors have been an industrialized product, serving primarily the medical and science communities’ needs for high performance magnets. The last decade has seen a rapid divergence between the requirements of these two user communities. Superconductor use in medical diagnostics, analytics and treatment is well established. Cost and reliable high-volume supply...
Cancer therapy using high-energy carbon beams from the Heavy Ion Medical Accelerator in Chiba (HIMAC) has been carried out at NIRS since June 1994, and more than 10,000 patients were treated by now. With the prospective clinical results for the first ten years, we designed a compact accelerator facility for carbon-ion radiotherapy (CIRT), and performed related R&D works for widespread use of...
Intense magnetic fields provide experimentalists with a particularly versatile thermodynamic parameter that addresses a wide range of modern questions in physics and materials research. However, the generation of intense fields, including the proposed 60T DC magnet and 150T non-destructive pulsed magnet, requires continued development of high-strength materials and high-current-density...
Magnetic Resonance Imaging, MRI, is a powerful medical diagnostic tool and the largest commercial application of superconductivity. MRI magnet design is determined by competing requirements including functional performance, patient comfort, ease of siting in a hospital, minimum acquisition and lifecycle cost. The increased center field, maximized uniformity volume, minimized field decay and...
The latest CLIC damping ring lattice is based on magnets with longitudinally variable dipole fields in order to achieve ultra-low beam emittance, while keeping the ring circumference small. These magnets need to provide a focusing gradient of 11 T/m as well. The good field region radius is 5 mm. The field harmonics shall be in the order of 1E-4 of the main one. Since only a small variation of...
Advanced Conductor Technologies has been developing Conductor on Round Core (CORC®) cables and wires wound from REBCO coated conductors for use in high-field magnets. An overview of the current status future developments of the CORC® cables and wires is presented. CORC® cables with thickness of 5 to 8 mm have been developed for use in larger magnets that require only very limited bending of...
Coated conductors are now being considered for use in beam steering and focusing magnets for high energy particle accelerators. However, coated conductors and cables have substantial magnetization, important for field quality. Magnetization decay, although suppressed, is also important for field quality retention. In this work we investigate the influence of applied current and selected field...
Neurospin is a neuroscience research center located in France at CEA Saclay. Since its opening in November 2006, several MRI equipment are operated. The facility will be equipped with an innovative Whole Body 11.7 T MRI magnet, as part of the Iseult/Inumac project, a French-German initiative focused on very high magnetic-field molecular imaging. The Iseult/Inumac magnet is an actively shielded...
Laser-target acceleration represents a very promising alternative to conventional accelerators for several potential applications, e.g. in nuclear physics and medicine. However, some extreme features, such as a wide energy and angular spread, make optically accelerated ion beams not immediately suitable for multidisciplinary applications. Therefore, in addition to improvement of laser-target...
The CORC cable is composed of several layers of helically wound HTS tapes on a round core with the winding direction reversed in each successive layer. The cable is flexible but the flexibility is limited by the critical strain value when causing breakage of the HTS layer. The cables for magnets in fusion reactors experience large mechanical and electromagnetic loads arising from cabled...
A test facility for storage ring based high energy photon source with a beam energy of 6 GeV, a circumference about 1300m, and an emittance about 59 pm•rad (HEPF-TF) is now under construction in china. Small aperture high gradient quadrupole magnets are important magnets in HEPS-TF. The design and manufacture of two prototype high gradient small aperture quadrupole magnets are finished. The...
We started developing REBa2Cu3O7-δ (REBCO) magnets for ultra-high-field MRI systems in 2013. Our final targets are 9.4 T MRI systems for whole-body and brain imaging. In the project, a conduction-cooled REBCO MRI magnet having a room-temperature bore of 396 mm was fabricated and tested in order to evaluate the magnetic field homogeneity and stability. The magnet composed of 60 single pancakes...
Two new record size ReBCO CORC Cable-In-Conduit-Conductors were designed and manufactured by CERN in collaboration with the CORC strand supplier ACT in Boulder, and tested in cooperation with the Sultan team at PSI. The cables in both conductors are of similar design and use the six-around-one cable layout with six CORC strands. The cables are 2.8 m in length, rated 80 kA at 12T/4.5K and...
The new HTS application project supported by New Energy and Industrial Technology Development Organization (NEDO) started on July 2016 in Japan. One of the targets of this project is to demonstrate the half-scale magnet resonance imaging (MRI) system using high-temperature superconducting (HTS) magnets with REBCO coils. In the first phase of this project (2016 – 2018), a three-tesla magnet...
The new magnet lattice of the European Synchrotron Radiation Facility (ESRF) will include 128 Permanent Magnet (PM) dipoles presently under in-house construction. It requires about 6 tons of high coercivity Sm2C017 permanent magnet material subdivided into 12,300 blocks. The choice of the permanent magnet technology is motivated by an energy-saving context, the compactness of the magnet...
This work is a contribution to the development of the technology for an MgB2 based cryogen-free superconducting magnet for a 3T whole body MRI system. Specifically, we demonstrate that a react and wind coil segment can be made using a high-performance in situ route MgB2 conductor and that the coil could be operated in conduction mode with low levels of temperature gradient. A multifilamentary...
Two prototype Nb3Sn cable-in-conduit (CICC) conductors were designed and manufactured for the Toroidal Field (TF) magnet system of the envisaged European DEMO fusion reactor. Though both conductors were designed to operate at 82 kA in a background magnetic field of 13.6 T, they reflect a different approach with respect to the magnet winding pack assembly. The first approach is based on React &...
Permanent magnet (PM) based systems offer a potential solution to one of the key issues in designing and running modern particle accelerators; the power draw from conventional electromagnet systems. A recent and ongoing collaboration between the CLIC project at CERN and STFC’s Daresbury Laboratory has resulted in the ZEPTO (Zero Power Tuneable Optics) project, a drive to reduce the financial...
1.5 T magnetic resonance scanner has been successfully completed and high resolution images have been acquired. It is based on 1.5 T superconducting magnet developed and manufactured within the russian Everest project with warm bore 90 cm. Peak field on the coil windings is about 3.5 T. The field homogeneity is about 1 ppm in 45 cm sphere, the magnet field stability is better than 0.02...
In this paper, we propose an improved wire structure that easily causes current bypass when the V2O3 material is applied turn-to-turn in 2G HTS no-insulation coils. A characteristic of the V2O3 material is that when a quench causes the coil temperature to rise the turn-to-turn resistance is lowered and current is bypassed. However, due to the high material resistance of the original 2G HTS...
A compact test bed was developed for the critical current evaluation for the High Temperature Superconducting (HTS) tape samples under transverse magnetic field. The test bed is composed of a conduction-cooled superconducting magnet and an insert dewar which HTS short sample is hold in liquid nitrogen. The superconducting magnet, which can provide 3.5T horizontal magnetic field in its vertical...
A magnetic gear is a device that shows characteristics of a gear through the magnetic force of a permanent magnet. Permanent magnets are attached to the input and output rotors and transmit power using magnetic coupling without mechanical contact. Due to the non-contact power transmission method, it is possible to solve the problem of noise and wear due to the friction of the mechanical gear....
Screening currents induced in HTS coils generate an irregular magnetic field. In particular, a large amount of screening currents are induced in REBCO tapes due to the tape shape, consequently a large screening current-induced fields is produced. Screening current-induced fields are a crucial problem for NMR/MRI applications. However, it is not easy to estimate screening current-induced fields...
To evaluate the critical current (Ic) of HTS tape in various temperature conditions, the cryostat with conduction cooling system is widely used with DC power supply. But the continuously increasing DC current affects the temperature rising of metallic parts such as copper terminal for conduction cooling, HTS tape holder, current leads, and contact parts by joule heating. The temperature...
Iron-free CCT magnet design offers many advantages, one being the excellent field quality and the absence of multipole components. However, edge effects are present, although they tend to integrate out over the length of the magnet. Many modern accelerator applications, however, require that these magnets are placed in an area of rapidly varying optics parameters, so magnets with greatly...
Recently, a high-temperature superconducting (HTS) generator module with brushless HTS exciter for large-scale wind turbines is suggested for improving the stability of the generator. The brushless HTS exciter is used for inducing the field current to the HTS module coil without power supply, current lead, and slip ring, and hence reduces total power loss. However, unbalanced field current may...
Superconducting magnets are required to be smaller and to use less electrical energy to generate higher magnetic fields for many applications. As a solution, Zhang et al. [1] suggested a magnetic lens using high-temperature superconducting bulks. However, the focused magnetic field kept decreasing at a rate of about 1.3%/hour even if the current flowing in the outer superconducting coil kept...
The principle of the induction heating is based on the Faraday's law of electromagnetic induction. High frequency AC current flowing through the working coil induces magnetic field to the designated direction. The induced magnetic field enables Eddy current to flow at the surface of the conduction material located in the magnetic field and the current flowing through the conductor produces...
The application of high voltage superconducting apparatuses is considered as one of the most promising countermeasures against the increased power consumption. In order to ensure the electrical safety of high voltage superconducting apparatuses such as superconducting transformers and superconducting cables, the electrical insulation design should be conducted considering aging...
A no-insulation (NI) winding technique has been utilized in high-temperature superconducting (HTS) coils owing to enhanced thermal and electrical stabilities as well as high mechanical strength. However, the charge-discharge rate of the NI coil is considerably slower than that of completely insulated coils. Although metal-insulation (MI) and partial-insulation (PI) winding techniques have been...
Recently, there have been sustained efforts to develop novel epoxy composites including various fillers for improving the physical properties of the epoxy-impregnated superconducting coil. Among the various filler materials, carbon nanotubes (CNTs) have emerged as one of the promising candidates because of the high thermal conductivity as well as the superior mechanical strength. However,...
An optimized NbTi-magnet lay-out has been designed for a Magnetic Density Separation (MDS) system. MDS is a novel recycling technology that allows the separation of non-magnetic materials based on their mass density. In the process, products are submerged in a ferro-fluid stream that flows over a magnet system which produces a strong vertical field gradient. The combined weight of the...
Due to the high efficiency, high power density and high flexibility for maneuvering and docking, electric propulsion systems for marine propulsion attract more and more attention in recent year. Generally, the motor for marine propulsion operates at a low speed which implies that the size of the motor tends to be large. By eliminating the transmission gear, the vernier permanent-magnet (PM)...
A 1 T Wide Aperture Vector magnet, WAVE Photons, dedicated to the soft x-ray experiment resonant scattering (SEXTANTS) beamline at Synchrotron SOLEIL, is developed by CEA, SOLEIL, Institut Néel and the Company SIGMAPHI. The scientists study electronic and magnetic properties under applied magnetic field using different techniques such as Resonant Inelastic X-ray Scattering (RIXS), X-Ray...
Although the high temperature superconducting (HTS) synchronous motors or generators has been proposed by lots of research groups, just a small number of them has been proposed a fully superconducting rotating machines with HTS conductors. One major reason for that will be AC loss problem caused by the alternating magnetic field applied to the armature windings. However, a fully HTS rotating...
Many investigators have reported the AC loss characteristics in a HTS multi-layered twisted cable. This experimental report describes the whole AC loss characteristics in HTS cable, and the AC loss distribution in each layer of the cable is based on a numerical method only. For this reason, the HTS cable is a twisted structure and a longitudinal magnetic field is generated. A voltage lead...
In order to elucidate AC loss characteristics of High-Tc superconducting coils wound by stacked conductors, we measured AC losses of Bi-2223 sample coils under the various electro-magnetic conditions by a nitrogen boil-off method. The sample coils were wound by stacked conductors, which were composed of two Bi-2223 tapes. Each tape of stacked conductors was wrapped with the polyimide tape, and...
For ac applications of superconductors, ac loss is most of the heat load. So it is very important to estimate the ac losses in superconducting windings for the design of cooling system. However the measurement of ac loss takes much time and cost and also needs large facilities. So simple and easy estimation method of ac loss is required. In this study we investigated the ac loss properties of...
REBCO superconducting tapes have great performance in critical current density, Jc, property even at liquid nitrogen temperature. However, it is necessary to enhance a current capacity according to various applications. We proposed the configuration of parallel conductors. The constituent strands of parallel conductors need to be insulated and transposed for even current sharing and low ac...
Magnetic fluid is a stable colloidal dispersion of single domain magnetic nanoparticles in a carrier fluid [1]. Magnetic fluid can be widely used in various fields [1-2]. Based on the magneto-viscous characteristic, magnetic fluid has many unique advantages as damping medium. This paper presents an adjustable magnetic fluid damper. This damper is composed of an induction coil, a non-magnetic...
Proton therapy for the treatment of cancers adopts a rotating system called gantry to irradiate the tumor from any direction. The gantry system consists of different beam line magnets that bend the proton beam towards the patient. The use of superconducting magnets allows reducing the size and weight of the last bending section. During the gantry operation, it is necessary to change the...
Mechanical gears have many applications in industrial machines and power transmission. Because of their contact mechanisms, the associated transmission loss, gear noise and regular lubrication are inevitable. Using coaxial topology and high performance permanent magnets (PMs), it was proposed that magnetic gears could be a valid replacement for the mechanical gear. Using high performance PMs,...
Low-speed high-torque machines are being increasingly used in various applications such as electric vehicles, wind-power generation, electric vessels, industrial robots, and home appliances, because they can offer direct-drive operation, which avoids the inconveniences of mechanical gearboxes. The magnetic geared permanent magnet (MGPM) machine, which works similar to an electrical machine...
Permanent magnet linear synchronous machines (PMLSMs) are able to provide thrust force directly to the load without mechanical gears and transmission; therefore, they have significant advantages over rotary machines, such as simplicity and high efficiency. Generally, PMLSM uses vertically magnetized permanent magnets (PMs). However, we proposed a PMLSM with horizontally magnetized PMs, which...
Electrical insulation of superconducting magnets represents one of the most critical aspects in the manufacturing and operation of these devices. In tokamaks, for instance, the use of superconducting magnets is highly recommended since superconductivity constitutes an enabling technology for fusion plasmas, nonetheless, their capability in withstanding off-normal loading conditions was never...
Permanent magnet couplings (PMCs) transmit torque without any mechanical contact. In particular, the axial flux magnet coupling (AFPMC) has the advantage of a compact and flat construction. Furthermore, it can achieve a high torque-to-weight ratio. Owing to the structural characteristics of AFPMC, its analysis requires the three-dimensional finite element method (3-D FEM). Analyzing magnetic...
The steady, increase in the demand for linear electrical machines in applications such as industrial robotics, transportation, manufacturing, and electrical power generation has been witnessed in recent times. Linear synchronous machines can be particularly operated without converting rotary motion to linear motion and have significant advantages such as simplicity, efficiency, positioning...
This study considered the reduction of the detent force of a permanent magnet linear synchronous generator (PMLSG). In general, the PMLSG has a relatively large magnetic air gap. Consequently, in the design of the PMLSG, its structure can be composed of single-sided and double-sided structures. The double-sided structure can produce larger force. The PMLSG also has a slotted-type stator...
High $T_{c}$ superconductor (HTS) could be a key to evolve the magnet technology as it is superior to low $T_{c}$ superconductor (LTS) in terms of the critical current density, critical magnetic field, and critical temperature. REBa$_2$Cu$_3$O$_{7-x}$ (REBCO) coated conductor (CC), which is in common use as the commercially available HTS, is suitable for fabrication of the magnet since it is...
Recently, no insulation (NI) and partial insulation (PI) techniques are proposed and studied for the compact and stable high temperature superconducting (HTS) coils. We have been studied the methods to improve the self-protection ability of HTS coils by removing the turn-to-turn insulation and inserting a metal tape instead of an electrical insulation. The operating current in the NI and/or PI...
A superconducting magnet able to provide the required field of 4 T has been developed for a compact cyclotron to produce radio isotopes for medical imaging, in the framework of AMIT project. It consists of two coils in Helmholtz configuration, embedded in a stainless steel casing to hold the Lorentz forces. The cooling scheme is based on a low pressure forced internal flow of two-phase...
When coated conductors are applied to devices whose transport current or applied magnetic field is time-dependent, ac loss in coils is a major issue which needs to be accurately evaluated and addressed. Electromagnetic field analyses are effective tools not only for evaluating and characterizing ac losses in entire coils wound with coated conductors, but also for estimating the ac loss density...
Solid insulation materials for superconducting applications are required to be robust in terms of both mechanical and electrical performance. The electrical insulation performance of gaseous medium is inferior to that of liquid medium. Also, the characteristics of creepage discharge is inferior to those of penetration breakdown. Therefore, electrical breakdown of a high voltage superconducting...
Thus far, RE123 coated conductors have revealed their promising potential for high field generating materials. On the other hand, RE123 bulks grown by the melt-solidification method, which can trap much higher magnetic field than permanent magnets, have been opening new superconducting applications, such as flywheels, magnetic separation, drug delivery, levitating mixer and compact NMR. ...
High-field magnets are often demanded for advanced scientific studies. Although a hybrid coil design comprising Nb-Ti, Nb3Sn, and HTS (High Temperature Superconductors) are potential candidates for such application, the costs of Nb3Sn and HTS are expensive compared with Nb-Ti. Permanent magnet can join hybrid magnets. By generating additional field about 1 T by permanent magnets, required...
We have designed a 4 tesla superconducting isochronous cyclotron for proton therapy. Its yoke weight is about 65 tons, which is less than one third of our normal-conducting 230 MeV cyclotron. Application of superconducting wire to cyclotron can contribute to reduction of dimension, initial costs, power consumption and lead time. The superconducting coils using NbTi wire are conduction-cooled...
In recent years, due to the highly variable cost of rare-earth permanent magnet(PM) and requirement for more efficient motor, PM-assisted synchronous reluctance machine(PMAREL) have attracted increasing attention and become one of the research highlights in the motor field. Generally, the PMAREL machines are characterized by a complex rotor structure, where multi flux barriers are set to...
Interior permanent magnet synchronous machine (IPMSM) have been widely used in many areas compared with the conventional motors for their advantages, such as high torque, high power, widely variable speed range and so on. Theoretically, IPMSM can be designed with an infinite speed range for constant power operation by utilizing flux weakening control method. But practically, in order to...
For the applications of proton therapy and proton irradiation, and based on the R&D starting from 2009, a construction project of a 230 MeV superconducting cyclotron (CYCIAE-230) has been launched at China Institute of Atomic Energy (CIAE) since Jan 2015. A compact main magnet design with warm iron yokes and a superconducting coil system is adopted to reduce the size, and consequently to lower...
Brushless doubly-fed generator (BDFG) is particularly suitable for using in variable speed constant frequency wind power generation system due to its inherent characteristics. The two sets of stator windings with different numbers of magnetic poles are coupled by magnetic field modulation of a special rotor, so the rotor structure directly affects the performance of BDFG. The commonly used...
A multi-stage induction type coilgun system is one of the most important research items. Especially, the capacitor driven induction coilgun, which is almost free from physical contact between the barrels and projectile, has a longer gun lifetime compared to other electromagnetic launchers. Accurate analysis of multi-stage induction coilgun is usually necessary to establish full-size finite...
HUST proton therapy facility is a Major State Research & Development Program supported by MOST, China. This facility is based on an isochronous superconducting cyclotron with two gantry beam lines and one fixed beam line. This paper will discuss the beam optics and main magnetic elements including dipoles, quadrupoles and fast scanning magnets of the gantry beam line. As well as the Energy...
Recently, high-speed electrical machines are being used at an increasing rate owing to the numerous advantages of high-speed compressors such as high efficiency, simple structure, high power density, and small size. Researchers have proposed various electromagnetic designs for high-speed permanent magnet (PM) machines. However, for high-speed PM machines, mechanical stresses are generated in...
For the Future Circular Collider (FCC), a 100 TeV post Large Hadron Collider machine, 750 main quadrupoles with a gradient of around 400 T/m are required. This paper presents an electromagnetic design optimization of a double aperture Nb3Sn quadrupole fulfilling the specifications, and, a structural design of a single aperture configuration towards a prototype.
Hybrid thrust magnetic bearing(HTMB) for heavy rotating shaft should be considered axial load at initial design stage since as the load increases, the force is generated asymmetrically. Therefore, the force acting on the upper part and the force acting on the lower part must necessarily be designed in different ways. In the case of a vertically driven shaft with a heavy impeller mounted...
A proton therapy project HUST-PTF (HUST Proton Therapy Facility) based on a 250 MeV isochronous superconducting cyclotron was under development in Huazhong University of Science and Technology (HUST). In this paper we reported the main design considerations of the beam line in HUST-PTF project. As well as two prototype magnets (one quadrupole and one dipole) were designed. Two-dimensional...
Cost-effective superconducting dipole magnets with operating fields up to 16 T are being considered for the LHC energy upgrade (HE-LHC) or a Future Circular Collider (FCC). To demonstrate feasibility of 15 T accelerator quality dipole magnets, Fermilab as a part of US-MDP has started the development of a single-aperture Nb3Sn dipole demonstrator based on a 4-layer graded cos-theta coil with 60...
Magnetic hyperthermia is expected as a thermal ablation cancer therapy. For the induction heating of the nano scale magnetic beads, the required specifications of the high frequency magnet are 0.06 T and 200 kHz of the AC magnetic field with 5 minutes of the continuous or intermittent operation time. However, the magnet system requires the enough bore size for the cancer therapy. Addition to...
Superconducting MgB2 wire is characterized to analyze the optimum working point of a magnet system for magnetic density separation (MDS) in terms of the magnetic field and operating temperature. MDS is an innovative recycling technology that selectively separates particles in a waste stream based on their mass density by suspending them in a ferro-fluid that flows through a strong vertical...
We already reported the capability of DC induction heating with the superconducting magnet to supply melting metal of required amount in a short time to the die-casting, in 2015. Many of complex geometries of aluminum profiles for automotive, transportation and industrial equipment are formed by the die-casting, and highly efficient metal melting technology for die-casting is required. We...
Eight highly saturated dipole magnets have been developed for the Shanghai Advanced Proton Therapy booster. The field reaches 1.77 T at the design current of 1200 A. The homogeneity of the integrated field is better than 0.001 within a good field region width of 100 mm. The integrated field consistency for the 8 dipole magnets is better than 0.003. The design and the measurement results for...
The high intensity muon beam line is required for the next-generation experimental search for the muon-to-electron conversion, such as PRISM project and the muon collider for the NuFact project. Currently, a muon beam line for COMET experiment is under construction, and the pion capture solenoid system faces the radiation issue. Radiation exposure (neutron fluence: 5$\times$10$^{21}$...
PM linear machine is an important category of PM machine, which is suitable for rail transit. The existence of the end effect will cause the unbalanced back-EMF, which can enlarge the ripple of the thrust. A novel linear vernier mover-PM (LVMPM) machine will be proposed in this paper. It is economical to be used in long distance. The characteristics of the proposed machine are analyzed by...
An embedded flexible inductor constructed using Fe-Si-Al powder composite films and a low power DC-DC converter using this inductor are proposed. Composite films, with a μR of 40, are composed of mixed Fe-Si-Al flaked powders and ethylene propylene diene monomer (EPDM) rubber. The embedded flexible circuits have etched spiral copper traces with 18 turns for two layers. The copper trace is...
(RE)BCO commercial coated superconductors have gained an increasing interest for its use in high magnetic field magnets. The leading project is the 32 T DC user magnet to be commissioned soon at the National High Magnetic Field Laboratory, Florida, USA. This state-of-the-art high field all-superconducting magnet, bath-cooled at 4.2 K, is comprised of a two-coil insert pancake-wound with...
In the circumstances of the bulk transport of current lead in a magnet, HTS DC cables used as current leads for the magnets have great advantages. However, the AC loss is one of the important parameters of HTS DC cable and it has a strong effect on its stability and operation cost. For this research, a cold dielectric HTS DC cable, consisting of one conductor layer, one insulation layer and...
The Ag-sheathed Bi2223 tapes have been extensively used for practical applications, while it is thought that the Jc properties of the Bi2223 polycrystalline materials were severely limited by the weak grain coupling originated in short coherence length with large anisotropy. Although control of the microstructure is known to be effective to improve critical current properties,...
Nb3Sn magnets with a nominal operation field of 15-16 T are being considered for the LHC energy upgrade (HE-LHC) and a post-LHC Future Circular Collider (FCC). To demonstrate the feasibility of 15 T accelerator quality dipole magnets, the US Magnet Development Program (MDP) is developing a single-aperture 15 T Nb3Sn dipole demonstrator based on a 4-layer graded cos-theta coil with 60 mm...
Magnetic fluid is a kind of magnetic functional material. In a gradient magnetic field, a permanent magnet can be suspended in the magnetic fluid by the second-order buoyancy due to the magnetic force. Based on this principle, the passive magnetic fluid damper is proposed. Much work has been researched in the field of magnetic fluid and magnetic fluid damper [1-2]. However, there is no...
The flux characteristics of a single-phase tubular permanent magnet linear motor (TPMLM) is analyzed with magnetic equivalent circuit (MEC) method in this paper. The flux linkage of the proposed single-phase TPMLM is generated by the permanent magnets and the bread type windings. The magnetic lines of flux travel through the stator yoke, the stator sleeve, air gap, and the mover to form a...
As part of the Large Hadron Collider High Luminosity upgrade (HL-LHC) project, 11 tesla Nb3Sn dipole magnets will replace some of the existing 8.33 T Nb-Ti LHC main dipole magnets. The 11 T dipole coils are mechanically loaded through a removable pole wedge. The force exerted on the Ti6Al4V pole wedge is transmitted onto the coils via tangential sliding of the wedge on the coil shims and...
The superconductors based on magnesium diboride have a lot of advantages in compare with traditional ones, such as relative simplicity of the superconducting compound synthesis process, small weight of finished product, possibility to manufacture superconductors in form of wires and tapes, absence of superconducting properties anisotropy. In this work the results of manufacture and study of...
The future upgrades of the CERN accelerator chain along with the future high energy colliders, notably the FCC, will require high gradient quadrupoles. As part of the HL-LHC project, the 11T Dipole was the first Nb3Sn magnet designed from the beginning to be compatible with the accelerator requirements and industrial production. It is based on the “pole-loading” concept, in which the Ti-alloy...
If a quench occurs in an HTS magnet, it is almost impossible to protect the magnet from being burned. So far, it was usual to wind a magnet with insulated wires. However the insulated magnets are easily burned by a quench. To solve this problem no-insulation winding technique is developed recently. A no-insulation magnet shows very stable performance. However this magnet shows very poor...
The continuous advancement of superconductors has empowered numerous industrious, power system, and military utilizations. The performances of MgB2 expand the utilization of superconductors through power transmission, power generation, transportation vehicle, propulsion vessel and several other applications. The proposed higher-level model provides a computationally-efficient tool capable of...
Transcranial magnetic stimulation (TMS) is a modern technology for non-invasive modulation of the cortical tissue excitability in specific brain regions. Because of better focalization, planar Figure of Eight (FOE) coil is most widely used in magnetic stimulator nowadays, whereas it has two negative peaks besides the positive peak of interest and the ratio of peak value to negative peak value...
A glass fiber reinforced plastic (GFRP) has been widely used for electric insulation in a high temperature superconducting (HTS) winding. Since thermal conductivity in the GFRP is low, the GFRP makes thermal flow from the superconducting winding to a cold head of a refrigerator worse. When a high thermal conduction plastic is used instead of the GFRP, the cooling performance in the winding...
In automatically wound machines, the actual position of each single conductor in the slot is usually unknown. However, depending on the individual placement in the slot, parallel-connected strands can lead to differing circulating currents. Since the flux-linkage due to leakage flux in the slot varies in radial direction, increasing towards the slot opening, the induced voltage also differs in...
Recently, integrated motor propulsors (IMPs) have been under extensive research and development because of the numerous advantages of underwater propulsion for vehicles. IMPs require minimized torque ripple for smooth and quiet operation when used in undersea vehicles or unmanned submarines. Thus, torque ripple reduction should be considered in the design stage. In the IMP case, a permanent...
We studied the levitation separation for precious metals utilizing magneto-Archimedes effect in high gradient magnetic fields. In order to enhance the magnetic force cylindrical ferromagnetic materials were set into a 10 T superconducting solenoidal magnet. The power factor of BgradB for magneto-Archimedes force reached the high value over -1000 T2/m by the optimum arrangement of ferromagnetic...
Assembled coated conductors are essential in many high current HTS applications. There are two ways to achieve assembled coated conductors. One way is to vertically stack the coated conductors, and the other is to use continuously transposed Roebel cables. In addition to high current carrying capacity, Roebel cables offer both low AC loss and mechanical flexibility. In this work, we measured...
A mechanical spur gears inherently suffer from the drawbacks of high transmission loss, bulky size, high noise, wear-and-tear. In order to alleviate these problems, magnetic spur gears are designed which use the magnetic force. They offer the advantages of reduced silent operation, overload protection and maintenance fee. As the magnetic spur gear diverges in all directions according to the...
The high temperature superconducting (HTS) conductors with low AC losses are essential for the HTS power devices. There are many studies for the development of 2G HTS conductor with the low AC loss and large current capacity, such as Roebel assembled coated conductors (RACC), conductors on round core (CORC), twisted stacked tape cable (TSTC), coated conductor Rutherford cable (CCRC), and so...
AC loss and eddy current loss are inevitable in AC HTS (High Temperature Superconductor) magnets and even in DC HTS magnets under varying magnetic field or current. To secure thermal stability, especially in the conduction cooling, reduction of contact thermal resistances (CTR) is one of the crucial factors. To avoid the delamination problem, epoxy is not usually used between turns of ReBCO...
CCT technology promises, by its intrinsic stress-management, to lower coil stresses in high-field accelerator magnets. This is especially relevant for Nb3Sn magnets, which may be subject to irreversible degradation if the coil stresses exceed critical values. The internal structure of CCT coils, however, dilutes the engineering current density. For an efficient design, the internal structure,...
The cable-in-conduit conductor (CICC) that will be adopted for the 3L module of the ITER Central Solenoid (CS) coil and for the Toroidal Field (TF) magnets of the ITER Machine have been extensively characterized in the SULTAN facility in Villigen, Switzerland by means of DC and AC tests. The AC tests were performed superimposing a sinusoidally varying magnetic field, with amplitude of 0.2−0.3...
The magnetization loss model in HTS tape when the magnetic field is exposed to the HTS tape face is suggested to be a Brandt model. In the case of a thin HTS tape, when the magnetic field exposed perpendicular to the HTS tape axis and the tape face is rotated, the magnetization losses correspond with Brandt model when the linkage magnetic field exposed. We previously reported the AC loss...
Dipole and Quadrupole magnets or a combination of both with rather strong magnetic fields are required in many medical applications. Although such magnets can be built with warm temperature electromagnets, under certain physical conditions such electromagnets can be replaced by Halbach type permanent magnets in combination with rather small inexpensive electromagnets to provide variability of...
Compensated pulsed alternator (CPA) is a kind of device supplying power for pulsed equipment such as pulsed laser, accelerator and electromagnetic railgun. The most widely researched scheme of CPA is the air-core self-excitation one which is capable of supplying high current and power. But it needs a bulky capacitor to provide seeding current and a prime motor which complicates the power...
It is important to achieve sufficiently low joint resistance (RJ), such as order of nano ohm, in ITER TF coils. However, a huge equipment is necessary to measure RJ at 4 K because of huge mass and size of TF coil. On the other hand, according to experiences by the authors, good RJ could be successfully achieved in ITER EDA model coils. In addition, severe process control is being done in ITER...
This paper presents a novel 16/12 outer module rotor-type switched reluctance machine. Unlike conventional structures, the rotor of the proposed structure includes a series of discrete module, and every outer module rotor is U-shaped structure and has two rotor pole. Each phase winding is composed of two series coils wrapped on two stator teeth. The short flux paths can be generated by excited...
In order to achieve high efficiency over wide-speed operation, variable flux memory motor (VFMM) has been proposed. This new class of motor can control the magnetization state by applying direct-axis (d-axis) current pulses. When designing VFMM, it is important to study nonlinear magnetization state considering the electrical constrains, since the PM magnetization strength must be controlled...
The Pre Compression Ring (PCR) is an important element of the ITER magnetic system since it improves the force distribution among the Toroidal Field magnets during plasma operation. An experimental campaign has been planned at Iter Organization (IO) to characterize the mechanical behaviour of the ring in a test rig able to simulate the ITER assembly conditions. In particular the testing...
In the framework of the Future CERN Collider (FCC) studies, and in order to reach 100 TeV collision energies, 16 T dipoles are under development. To allow for a more compact and cost-effective design, the coils need to be graded. This paper presents a 2D parametric study which explores possible options for an optimal grading. This study uses both analytical formulas and FE analysis. Block...
The high strength conductors used in pulsed magnets in the US National High Magnetic Field Laboratory (MagLab) are manufactured from Cu matrix composites. One of the composites is made from particle reinforced Cu. The fabrication of these composite conductors requires high deformation strain, which creates high densities of dislocations and reduced particle spacing. Both mechanical strength...
Magnesium Diboride (MgB2) superconductors with 11B serving as the boron source, is a potential candidate as an intermediate superconductor in thermo-nuclear fusion reactors having higher neutron flux environment. 11B in elemental form is known to be stable against fast neutron irradiation with significantly lower and reduced radioactive properties. Scientific Research Council of Department of...
As All Electric Ship (AES) capacity increasing dramatically, load fluctuation of such systems may cause serious problems, such as voltage fluctuation of the ship power grid, increasing fuel consumption, and environmental emissions. In order to reduce the effects of system load fluctuations on system efficiency, and to maintain the bus voltage, a Hybrid Energy Storage System (HESS) is...
The electromagnetic-thermal model for Cable-in-Conduit Conductors JackPot-ACDC and THEA (Thermal, Hydraulic and Electric Analysis of superconducting cables) are combined for prediction of the stability of ITER Central Solenoid conductors. The combination of both models allows to predict the effect of any type of magnetic field perturbation in time relevant for the magnet coils during the...
Large-scale racetrack coils wound with two kinds of REBCO-coated conductors were developed and tested. The two conductors had different critical currents, thicknesses and also allowable delamination stresses respectively for comparison. The total wire length of the fabricated two coils was 978 m and 945 m, and the overall size was 0.57 m x 1.14 m and 0.51 m x 1.08 m. The coils were impregnated...
WAVE is a one tesla superconducting vector magnet for neutron scattering experiments. It will expand the range of experimental scattering possibilities by being able to applying a 3D magnetic field in any orientation, completely independently from orienting the sample in diffraction condition. WAVE will be used as a sample environment on neutron scattering instruments relevant for magnetism...
Fully superconducting machine is the one that can take the most advantages of superconducting materials with dramatically improving the magnetic loading and electrical loading at the same time. However, intense R&D effort is giving priority to partially superconducting machines not only for their lower manufacture difficulty but also higher feasibility compared to fully superconducting...
REBCO coated conductor has architecture of metal substrate/ buffer layers / REBCO layer/ metal over-layers. Multilayer thin films are deposited on metal substrate by various deposition or coating technique. From this structures, films delamination and interfacial failure in coil applications are caused by thermal mismatch strains and potentially high Lorentz forces. We have proposed advanced...
Brushless doubly fed machine (BDFM) is a new type of adjustable-speed machine developed in recent years. It has broad application prospects in the field of variable frequency speed regulation and wind power generation. However, the traditional loss calculation method is no longer applicable due to the special structure and complex magnetic field distribution of BDFM. A novel hybrid rotor...
Brushless doubly fed generator (BDFG) has a broad application prospect in variable speed constant frequency offshore wind power generation system, in recent years, MW-class generators for offshore wind turbine has been becoming the hot-spot of research. Due to the large volume of MW-class generators, if the solid rotor is used, there will be some difficulties in the process of transportation...
Current proton therapy scanning systems always use two inde-pendent dipole magnets for spot scanning in proton therapy. However, the space occupied by these two dipole magnets locat-ed after the final gantry bending magnets is very large and in-creases the overall size of the gantry. In order to construct a compact nozzle and decrease the size of the gantry, we decide to design an octupole...
The PETAL (PETawatt Aquitaine Laser) laser facility is a high energy multi-petawatt laser, which is able to generate pulses of up to 3.5 kJ energy with a duration of 0.5 to 5 ps. This petawatt laser will be coupled with the ns pulsed beams of the LMJ (Laser MégaJoule). Such facility will provide unique tools for inertial confinement fusion (ICF) physics. PETAL is located in the site of the...
Cu-6wt.%Ag micro-composites were fabricated via casting and accumulative bundling and drawing (ADB) process. The evolution of microstructure and crystal orientation during the compositing process was observed. The mechanical properties and conductivity characteristics of the materials were investigated. And the mechanism for the mechanical properties was discussed.
We present a Finite Element Method (FEM) analysis of stability, heating and quench propagation in a conduction cooled race track coil at 20 K. The coil was assumed to be wound using YBCO coated conductor tape either non-insulated or insulated by a kapton tape. An anisotropic continuum model of the winding for thermal propagation, with input parameters taken from experiments, was developed and...
High field magnets built using low temperature superconductors are currently approaching their upper field limit of 25T or so. Applications of (RE=Y, Gd)BCO coated conductors for the generation of high magnetic fields are increasing sharply, this while (RE)BCO coated conductors themselves are evolving rapidly. This present study simulates the stability of a new magnet made of ring-shaped YBCO...
The intersection regions and the beam injection channel of a high-energy collider require magnets that must act strongly upon one beam yet not at all on a closely neighboring beam. Designs are presented for three examples: a septum dipole that serves as a forward spectrometer centered on an ion beam after collision, which must clear an electron beam leaving the IP; a final-focus quadrupole...
The development of the Toroidal field coils of the upcoming European DEMO reactor is under the coordination of the EUROfusion Consortium. The Swiss Plasma Center (SPC) and ENEA-Fusion produced two new cable concepts, RW1 (react and wind) and WR1 (wind and react) with rectangular cross section, inspired by existing concepts of Nb3Sn Cable-in-Conduit Conductors (CiCCs). The prototypes have been...
A 25 T all-superconducting magnet, consisting of a 10 T GdBCO high temperature superconducting (HTS) insert and 15 T low temperature superconducting outer coils, is now in progress at Institute of Electrical Engineering, Chinese Academy of Sciences. Predicting the stress/strain distributions inside the HTS insert during its fabrication and energization accurately is one of the key issues to...
We report that the strong flux pinning of (Ba, K)Fe2As2 thin films is induced by the superconducting phase distribution characteristics. Depending on the growth conditions, our thin films have distribution diversity which can induce various superconducting properties. The activation energy is one of the parameters representing pinning forces. We compare the activation energy of two different...
Reinforced round and rectangular, Bi2212 -based, high temperature superconducting wires are being developed for use in transposed cables, coils and magnets that are problematic with wide HTS tapes, and that need to operate beyond the limits of low temperature superconductors. These wires exhibit in excess of 500 MPa stress tolerances and current densities (Jc’s) that exceed 2000 A/mm2 at >...
A novel methodology is proposed for the structural optimization of the inner-leg cross-section of Toroidal Field (TF) coils of DEMO fusion reactor to achieve significant improvements in the structural response of the component. The original Winding Pack (WP) configuration, used as starting point of the optimization process, despite being compliant in terms of the electro-magnetic behavior,...
Brushless doubly-fed generator (BDFG) has the advantages of reliable structure, easiness in implementing variable-speed constant-frequency, small converter capacity, and so on, which has a broad application prospect in large offshore wind power generation. There are two sets of windings with different pole numbers on the BDFG stator, which are respectively called the power winding for...
Started in Jan 2015, a 230 MeV superconducting cyclotron is under construction at China Institute of Atomic Energy for proton therapy. A compact main magnet design with warm iron yokes and a superconducting coil system is adopted to reduce the size, construction and operation cost of the cyclotron. In this paper, the field calculations of the main magnet are briefly described; then the R&D of...
Superconducting properties of CeO2 doped and undoped YBCO superconductors were evaluated to investigate the effect of pinning center on the magnetization properties. The variation △M with doping was maximum for 5 wt% doping and decrease with further doping. The result indicates that △M is propotional to the number of magnetic flux lines passing through the sample. The CeO2 was converted to...
High temperature superconducting (HTS) wires such as first generation Bi-2223 Ag-sheathed tape and second generation rare-earth-based coated conductor have been developed and become commercially available. When the HTS coils wound using these wires are energized, the in-plane screening currents induced in the windings due to the perpendicular components of locally applied magnetic fields not...
The JackPot-ACDC model, an electromagnetic-thermal model for Cable-in-Conduit Conductors and THEA, a thermo-hydraulic model for superconductors can be combined to reproduce and predict the behavior of a conductor under any current and magnetic field variations. JackPot+THEA is used to model the most demanding turns of the CSU2 module quadra-pancake of the ITER Central Solenoid. The chosen...
Mechanical gears, which are employed in the many fields of modern industry, are used mostly for power-transmitting mechanical devices. However, because the mechanical gear operates, in principle, by the engagement of gear teeth, it is difficult to avoid problems such as friction loss from physical contact, noise, and vibration. To address this problem, magnetic gears have been proposed as a...
Many researchers have a great interest in applying no-insulation (NI) REBCO pancake coils to high field magnets used for NMR, MRI, and accelerator applications, because NI REBCO pancake coils have a high thermal stability. When a local normal hot spot appears in an NI REBCO pancake coil, the operating current can flow from the turn to the adjacent turns so as to avoid the hot spot. In other...
As a turn-to-turn insulation material on second generation high-temperature superconducting (2G HTS) coils, the smart insulation (SI) with a metal–insulator transition (MIT) materials, which have a resistivity variability on temperature, i.e., resistivity of MIT materials is decreased with temperature increase, may enhance not only the thermal stability but also current control performance of...
The superconducting magnets for the LHC High Luminosity upgrade (HL-LHC) are built using Nb3Sn technology, which implies a reaction heat treatment when the conductor is at final shape. During the reaction heat treatment the Nb3Sn coil is surrounded by a fixture that restricts the coil volume changes. The knowledge of the evolution of the thermo-mechanical properties of the coil materials and...
Ferrite-assisted synchronous reluctance motors (FASRM) provide high torque density and a wide range operation speeds for many applications, ranging from electric vehicle and electric home appliance. However, the main drawback of the FASRM is the high torque ripple. This paper is to propose a method of reducing total ripple by changing the opening angle of flux barrier. The key of this method...
The uniaxial strain induced the critical current degradation of Bi-2212 Ag-sheathed round wire was studied at 4.2 K in 14 T background field. The strains applied on the sample are both tension and compression. An additional tensile strain caused by the difference of thermal expansion between Bi-2212 round wire and Ti-6Al-4V was calculated. Results show that a drastic degradation of the...
A comprehensive study of upper critical (Hc2) and irreversibility magnetic fields (Hirr) in (Ba0.6K0.4)Fe2As2, Ba(Fe0.95Ni0.05)2As2, Ba(Fe0.94Ni0.06)2As2, Ba(Fe0.92Co0.08)2As2, and Ba(Fe0.92Co0.09)2As2 polycrystalline bulk pnictide superconductors for different average grain sizes was made in pulsed fields at the Los Alamos National Laboratory. The magnetic field-temperature (Hc2-T) phase...
Magnetically controlled saturated reactors (MCSRs) operate through changing the degree of saturation of the magnetic valve by applying different DC excitations. Due to the special structure and working mode of AC and DC excitation, the vibration of MCSRs is larger than that of the ordinary ones. In recent years, research on MCSRs vibration mainly concentrated on the causes of the MCSRs...
In the framework of the development of high field magnets made of Nb3Sn superconductor for projects like HL-LHC and FCC studies, it is needed to refine the understanding of the winding process and its impact of the overall mechanical integrity of the conductor. The mechanical behaviour during winding of the unreacted Rutherford type Nb3Sn cables has been studied experimentally. In order to...
National Institutes for Quantum and Radiological Science and Technology (QST) has responsibility as Japanese domestic agency (JADA) to procure 9 Toroidal Field (TF) coils in the ITER project. The high mechanical and electrical reliabilities have to be ensured for the operation of the ITER for 20 years. For this objective, the Radial Plate (RP) structure is employed to avoid accumulating the...
YBCO coated conductors are candidates for using in a number of High Energy Physics applications, like e.g. high field solenoids for muon colliders. A new approach in making YBCO magnets has been suggested recently, where the coils are neither insulated nor epoxied. It is believed that in this approach, the coil is much easier to protect, because once a given zone becomes normal, the lack of...
Zylon fibres are used at the National High Magnetic Field Laboratory for structural reinforcement of high field pulse magnet coils. We have studied the fibre properties with respect to the aging effect and light resistance. The high modulus and strength values were associated to the crystalline and texture. Long time exposure to lab-light was found to decay the crystallinity, increase...
CFETR (China Fusion Engineering Test Reactor) concept design work was started in 2012. It is developed in two stage. CFETR-Phase I is designed with major radius R=5.7m, minor radius a=1.6m and magnetic field at plasma region BT=4-5T. 16 toroidal field coils and 6 central solenoid coils were designed by Nb3Sn CICC with maximum operation current of 64 kA and 50 kA, respectively. Three types of...
CERN and LARP (LHC Accelerator Research Program) are jointly developing Nb3Sn quadrupole magnets to be installed in the LHC for its upgrade to higher luminosity. The quench protection system of these magnets will include a combination of quench heaters attached to the coil surface and CLIQ units electrically connected to the coils. This solution provides an effective reduction of the coil’s...
In high temperature superconducting (HTS) magnet applications, quench detection is very important to protect magnets before burning out. However, due to a very slow quench propagation of HTS wires compared with low temperature superconducting (LTS) ones, conventional quench detection methods are not suitable for HTS magnet: The method is that continuously measure resistive voltages on voltage...
The development of Nb3Sn quadrupole magnets for the High-Luminosity LHC upgrade is a joint venture between the US LHC Accelerator Research Program (LARP) and CERN with the goal of fabricating large aperture quadrupoles for the LHC interaction regions (IR). The inner triplet (low-β) NbTi quadrupoles in the IR will be replaced by the stronger Nb3Sn magnets boosting the LHC program of having...
The possibility to trigger the proton-boron nuclear fusion reaction (p + 11B → 8.5 MeV + 3a) by using a nsec class laser has been recently demonstrated. This is of high interest since such reaction does not produce any neutrons but just three alpha-particles, which could be used for applications in different fields. The possibility to confine the plasma fuel generated during laser-target...
The paper describes intricate cross coupling of quench detection and energy extraction systems to protect a hybrid dipole magnet built with Low Temperature Superconductor (LTS) outer coils and High Temperature (HTS) inner coils during the quench. Quench characteristics of HTS and LTS are quite different and various different parameters had to be considered in designing reliable quench...
The interplay between a nuclear fusion plasma and the reactor wall determines the performance and lifetime of fusion reactors. DIFFER's main experiment Magnum-PSI is the only laboratory setup in the world capable of exposing materials to plasma conditions similar to those of future fusion reactors. The success of the Magnum-PSI experiment depends on the generation of a 2.5 T magnetic field...
In the framework of the High-Luminosity upgrade of the Large Hadron Collider, the US LARP collaboration and CERN are jointly developing a 150 mm aperture Nb3Sn quadrupole for the LHC interaction regions. Due to the large beam size and orbit displacement in the final focusing triplet, MQXF has challenging targets for field quality at nominal operation conditions. Three short model magnets have...
The R&D method for the large Nb3Sn magnets of the EUROfusion DEMO device was proposed since 2013 by the Swiss Plasma Center. A first prototype conductor (RW1) was tested in the EDIPO test facility in 2015 up to 82 kA at 13 T, confirming the low thermal strain and the lack of cyclic load degradation. After the baseline of the DEMO device was updated in 2015, the new requirements led to an...
Sure quench protection of HTS coils is essential for their sustainable operations. The most probable cause of quench damages is the over-heating at the highest temperature spot (hot-spot) of the coil wire during the quench protection sequence. Therefore, to avoid the damage, generated heat in the hot-spot of the coil conductor has to be decreased by quick decrease of a current flowing in the...
The US LARP (LHC Accelerator Research Program), in collaboration with CERN, has started developing prototypes of the low-beta Quadrupoles (MQXF) for the High Luminosity Upgrade of the LHC at CERN. These large aperture (150 mm) high gradient (133 T/m) quadrupoles will use Nb3Sn conductor to replace the present 70-mm aperture NbTi quadrupoles.
The first LARP prototype (MQXFA1) has coils with 4...
Quench protection is the elephant in the room that no ones seems to see when it comes to HTS magnets. For the most part quench protection has not been much of a problem, because the stored energies of HTS magnets have been low compared to magnets made with LTS conductors. The principles of quench protection are the same regardless of the type of superconductor used. In general, a quench is...
Neutrons have a magnetic moment of around 60 neV/T. The force on this magnetic dipole moment in a gradient field can be used to manipulate or store so called ultracold neutrons (UCN), free neutrons with very small kinetic energy and velocity. To create a magnetic storage vessel, one has to create a low field region surrounded by a high field region; only one spin state of the neutrons can be...
The Laboratoire National des Champs Magnétiques Intenses (LNCMI) is a French host facility for experiments in high magnetic fields. Based on two sites, the LNCMI offers routinely static magnetic fields up to 36 T at its Grenoble site and pulsed magnetic fields up to 90 T using non-destructive magnets and up to 180 T using single-turn magnets at its Toulouse site. Internal research is carried...
The Dresden High Magnetic Field Laboratory (HLD) is a pulsed-field user facility which provides external and in-house researchers with the possibility to perform a broad range of experiments in pulsed magnetic fields [1]. Two independent, modular capacitor banks of 14 and 50 MJ with a maximum charging voltage of 24 kV deliver energy for ten mono-coil and dual-coil pulsed magnets generating...
An 18 T 70 mm cold bore high temperature superconducting (HTS) magnet was developed for axion detector system of Center for Axion and Precision Physics (CAPP) research center in Institute for Basic Science (IBS) in the Republic of Korea. No-insulation (NI) technique with metal cladding (MC) HTS tape was adopted for preventing damage from quenches. However, a NI magnet shows field lagging...
Segment-fabrication of high-temperature superconducting (HTS) coils has been proposed for huge and complex superconducting magnets. In Japan, the LHD-type helical fusion reactor, FFHR, designed by National Institute for Fusion Science, adopts the segment-fabrication for its helical coils as the challenging option. The fabrication method is called "joint-winding", in which the HTS helical coils...
A Neutron Spin-Echo (NSE) -spectrometer measures small velocity changes that neutrons undergo upon scattering at a sample. The velocity changes are encoded/decoded by the neutrons spin precession in large magnetic field before and after the sample. In order to achieve maximum sensitivity and efficiency, both a high value and a high precision of the magnetic field integral before and after the...
Abstract: The Poloidal Field (PF) magnet system of the International Thermonuclear Experimental Reactor (ITER) consists of six pulsed coils. Each coil comprises independent modules connected with “shaking hands” lap-type joints. The feasibility and stability of the plasma scenario requires the magnets to retain sufficient current and temperature margin. The joints essentially represent the...
The design of ITER Poloidal Coils contains 88 joints connecting individual conductors. Satisfying restrictions from operating condition, manufacturability and serviceability, these joints were designed as twin-box “shaking hands” concept. To ensure the manufacturing process consistently produces acceptable components, joint qualification tests have been defined for AC losses, DC resistance,...
The Muon Ionization Cooling Experiment (MICE) located at Rutherford Appleton Laboratory at England utilizes a superconducting solenoid system for the muon beamline that also holds particle tracking detectors and muon absorbers inside their bores. The solenoid system installation has been completed in summer of 2015 and after commissioning of the system it has been running successfully. This...
We present design and test results for a thermally-activated persistent-current switch (PCS) applied to a double pancake wound (DP) coil (151-mm ID, 172-mm OD), wound, using the no-insulation (NI) technique with a 120-m long, 76 micron thick, 6-mm wide REBCO tape. For the experiments reported in this paper, the NI DP assembly was immersed in a volume of solid nitrogen (SN2), cooled to...
In recent years Nb3Sn strand made by the internal tin process has been proven as an industrial scale high field conductor, previously by the high volume production for ITER and presently for the CERN High Luminosity upgrade. Strand manufactured by a flexible internal tin Nb3Sn method may be readily customized for particular applications. The challenge for particle accelerator applications is...
Tube type Nb3Sn conductor has been being explored by Hyper Tech Research Inc. Our standard conductor with 217 filament arrays have been generated with 12 T non-Cu Jc values of about 2400-2500 A/mm2 with filament size of 40 micros at the 0.85 mm strand. We also made 547 filament conductor which has filament size of 25 micros at the 0.85 mm strand without any drawing issue. This conductor...
Currently, how to measure the magnetic field accurately is a difficulty in the study of high magnetic field. This paper proposes a measurement method for pulsed magnetic field based on distributed magnetic field sensors. The method adopts multiple magnetic field sensors based on Rogowski coil to measure the value of the magnetic field. The magnetic field sensor is a single cube structure, of...
HTS dynamos are a class of superconducting flux pump, which have attracted significant recent interest as novel current sources for HTS magnet coils. They employ a series of permanent magnets which mechanically traverse a coated conductor stator, giving rise to a time averaged output emf. Previous work has shown that the maximum achievable output current of an HTS dynamo is determined by the...
Fermilab, as part of US MDP, is conducting Nb3Sn wire and cable R&D, with the goal of improving key properties and providing conductor specifications and data for design and construction of SC accelerator magnets for a future very high energy pp collider. SC wire R&D focused first on optimizing the regular Restacked-Rod Process Nb3Sn conductor by Bruker OST. Then, efforts were intensified on...
Superconducting and cryogenic environments are in use and under development for a large variety of Nanotechnology applications and Quantum technologies. Next generation of nanotechnology applications will be dependent on platforms that can probe and manipulate matter at the nanoscale under magnetic field and/or at cryogenic temperatures. This contribution presents an overview of a new class...
Sumitomo Electric has been developing silver-sheathed Bi2223 multi-filamentary wires, DI-BSCCO (Dynamically-Innovative BSCCO). The wires have been improved various properties in response to growing demands from application products and projects.
For high magnetic field applications targeting to more than several tesla, DI-BSCCO wires need to endure the intense hoop stress and maintain high...
The 2014 Particle Physics Project Prioritization Panel (P5) Report identified a critical need for transformational high field dipole magnet R&D, focused on improving performance and reducing the cost per T-m. This need was subsequently reiterated in the HEPAP Accelerator R&D subpanel report.
In response, the DOE Office of High Energy Physics has initiated an ambitious program to aggressively...
We present a compact, mobile pre-cooling cryogenic system (cooler) developed by Sumitomo Cryogenics as a solution that can significantly reduce helium losses associated with shipping medical MRI magnets globally. In contrast to conventional cold-shipping of MRI magnets, the cooler can enable MRI magnets to be shipped with the cryostat at room temperature, and then pre-cooled either during the...
A critical stage for any conductor technology, especially a wind and react (W&R) technology like Bi-2212 or Nb3Sn occurs when manufacturing becomes sufficiently mature for magnet use. This is now the case for Bi-2212, the only round wire, twisted, multifilamentary HTS conductor. Bi-2212 had fallen out of favor a decade ago because of its inferior Jc and complex heat treatment for W&R use. ...
Cryogenic technology is extensively used at DESY, FERMILAB, ITER, CERN, FAIR and ESS to create and maintain low-temperature conditions for the magnets. In order to operate at high magnetic fields, magnets are cooled with supercritical helium at 4 K (-269°C). They are surrounded by a large cryostat and an actively-cooled thermal shield with a forced flow of helium. Efficient cryogenic...
Dipoles with 15-20 T operating field are required for some designs of future hadron colliders. Such dipoles require the use of high-field superconductors Nb3Sn, Bi-2212, and REBCO. Designs are presented for block-coil dipoles using superconducting cable-in-conduit. This approach conveys several benefits that are important for high-field operation: cable-level stress management; compact,...
Many superconducting devices require higher currents which leads to the request for cables assembling single wires or tapes. MgB2 cables were developed with different geometries: twisted and braided cables, Roebel and Rutherford style geometries. MgB2 cables allow to make winding with small diameters without current degradation and reduce the AC losses through the lowered coupling loss. The...
Modelling the behavior of a superconducting magnet is challenging due to interdependent, nonlinear, multi-domain and multi-scale phenomena occurring during fast transients. A modelling technique based on a lumped-element equivalent system was recently proposed, which efficiently simulates electro-magnetic and thermal transients in a magnet. The model, named LEDET (Lumped-Element Dynamic...
A 25 Tesla superconducting magnet for NMR will be fabricated in the Institute of Electrical Engineering, Chinese Academy of Sciences. The magnet consists of HTS insert and LTS outsert with the central field contribution of 10 T and 15 T, respectively. Based on the features of HTS insert with respect to winding geometry and screening current, an electromagnetic design method is proposed. High...
Recently, we suggested a new bridge-type joint between two REBa2Cu3O7-δ (RE123, RE: Rare Earth such as Gd, Y) conductors using RE’123 (RE’: Rare Earth for low melting point of RE123, such as Yb, Y) bulk by heat treatment with crystal growth at boundary of wire-bulk. We call this method as crystalline joint by melted bulk (CJMB). In the CJMB method, only the bulk is incongruent melting that the...
Abstract— Future HTS high field magnets using multi-tape HTS cables need 10 KA low resistance connections. The connections are needed between the poles of the magnets and at the terminals in a wide operating temperature range, from 77 - 1.9 K.
The EuCARD-2 WP10 Future Magnets collaboration aims at testing HTS-based Roebel cables in an accelerator magnet. Usually, LTS cables are jointed inside...
Laser-based accelerators are gaining interest in recent years as an alternative to conventional machines. Nowadays, energy and angular spread of the laser-driven beams are the main issues in application and different solutions for dedicated beam-transport lines have been proposed. In this context a system of permanent magnet quadrupoles (PMQs) has been realized by INFN researchers, in...
To date, quite a number of no-insulation (NI) REBCO magnets have been designed and constructed, and all of them successfully generated their target fields. Some magnets experienced a quench at their full fields and survived without damage. The results have shown a potential of the NI REBCO winding technique for high field user magnets. Motivated by the recent progress, a 20 T...
A Bi2212-based rectangular wire approach has been developed, with up to 500 MPa stress tolerances and useful current densities for building compact solenoid coils that are more problematic to make with wide HTS tapes, and that need to operate beyond the field and temperature limits of low temperature superconductors. We are applying long lengths of this new Bi2212-wire to develop a practical...
Addressing an NHMFL goal of developing high temperature superconductor (HTS) technology applied toward nuclear magnetic resonance (NMR) at high fields (~1 GHz), the work presented here focuses on the finite element analysis (FEA) led designs of Bi2Sr2CaCu2O8-x (Bi-2212) round wire prototype coils. With the goal of an HTS insert coil that produces a significant portion (>20 %) of a combined...
Currently, we are conducting a collaborative R&D project to manufacture long MgB2 wires with a high critical current density, for developing helium-free MRI superconducting magnets, which is supported by the Materials and Components Technology Development Program of the Korean Evaluation Institute of Industrial Technology (KEIT), Korea. Herein, we report our progress on the superconducting...
We have succeeded in the development of the 25T cryogen-free superconducting magnet recently [1]. As a next step, a development of 30 T class superconducting magnet is planned. In order to realize high field superconducting magnets beyond 30 T, the reliability of REBa2Cu3Oy (RE123, RE: Y and rare earth) conductors should be improved. For this purpose, we made single pancake coils by co-winding...
We present results of calculations of the ultimate forces for the worst-case scenario, an important safety concern in hybrid magnets. They appear during a simultaneous and immediate burnout of some or all upper or lower resistive coil halves, or shorts between the coils in the mid-plain. Because of their intensity, they have a dramatic impact on the mechanical layout of a hybrid magnet. An...
A Bi2212-based rectangular wire approach has been developed, with up to 500 MPa stress tolerances and useful current densities for building compact solenoid coils that are more problematic to make with wide HTS tapes, and that need to operate beyond the field and temperature limits of low temperature superconductors. Until now, no method has been shown to achieve a superconducting joint...
Abstract: The high luminosity upgrade of the Large Hadron Collider (LHC) at CERN will consist of Nb3Sn based superconducting magnets operating at about 22kA DC. When these magnets quench, the power source has to be disconnected and stored energy should be discharged into a dump resistor very quickly. For this purpose, a 24kA DC current interruption switch based on Insulated Gate Bipolar...
From several years now at CEA/Saclay has been lunched a program that aims at developing design tools and technologies for conduction-cooled MgB2 magnets. In the framework of this program, a device for investigating the circumferential strain dependence of the critical current density in MgB2 wires and tapes has been designed. It has to be integrated into the existing test facility which...
INFN developed at LASA lab (Milano, Italy) a fast current switch in the framework of the EuCARD-2 project. A full prototype of a 10 kA fast switch based on insulated gate bipolar transistor (IGBT) modules operating in about 1 ms has been developed, installed and tested in the existing power supply at LASA lab. The upgraded power supply is meant to operate on the EuCARD-2 high temperature...
Research Center Jülich is responsible for the design and construction of the High-Energy Storage Ring as a contribution to the future Facility for Ion and Proton Research (FAIR) at GSI in Darmstadt, Germany. In particular curved dipole magnets with a length of about 4.2 m are being manufactured, and their magnetic field should be characterized in terms of their multipole content. For these...
In the last two decades, the linear permanent magnet (PM) machines which could directly realize linear movement without any additional transmission mechanisms converting the rotary motion into linear motion, are applied in direct-drive wave energy conversion (WEC) [1-4]. In particular, a conventional linear permanent magnet generator (CLPMG) reciprocates at such low-speed wave motions and...
For the quadrupole magnets of the Facility for Rare Isotope Beams (FRIB) at Michigan State University (MSU), the location of the magnetic center has to be known. The FRIB included 115 quadrupole magnets in seven kinds of specifications, to minimize the measurement time and cut the measurement costs, the IMP Magnetic and Machinery Department proposed a method using a rotating coil to measure...
Axial field flux-switching permanent magnet (AFFSPM) machine has the advantages of inherent sinusoidal back-EMF waveform, high power density, and large torque capability, which is suitable to use in electric vehicle (EV). However, the cogging torque of the AFFSPM machine is high and it is difficult to modify the flux, which limits the use in EV. In this paper, a novel multi-tooth axial field...
A prototype of multifunction test facility for providing cryogenic-electro- magneto-mechanical multi-fields to investigate the field-dependence properties of superconducting wires/tapes is recently constructed in our laboratory. The apparatus is self-designed with several relatively independent sub-systems. A superconducting racetrack magnet made of NbTi/Cu is used to generate a background...
Transcranial magnetic stimulation (TMS) is a technique that uses time-varying magnetic field generated by pulsed coil current to induce time-varying electric field in the brain. It has been widely applied to neurological disease treatment and brain function research. Presently, the maximum usable repetitive rate of the stimulator is up to 100Hz, and the coil current normally used in TMS...
This paper proposes a novel partitioned stator flux reversal memory machine (PS-FRMM, which is geometrically similar to the magnetically geared machines having surface-mounted PMs and armature windings on two separate stationary bodies. The proposed machines offer the merits of alleviating the conflict between electric and magnetic loadings, and hence the armature slot areas can be increased...
The co-wound voltage tap sensor is considered suitable to pulse operation superconducting coil quench detection but it has a fatal weak point.There is no way to repair it in case of sensor failure, since the co-wound sensor will be embedded inside the coil. A novel quench detection method is presented in this paper to detect a quench using radio frequency wave technology.The RF detection...
The NICA accelerator complex is being constructed in JINR, Dubna. It includes Electron String Ion Source, 6.2 Mev/u linac, 600 MeV/u booster synchrotron and collider. The booster will accumulate 4·109 Au32+ ions, accelerate heavy ions from 6.2 up to 600 MeV/u for Au32+ and form required beam emittance with the help of electron beam cooling. The cryogenic...
With ever improving performance of rare earth permanent magnet (PM) material, PM machines have been widely used. PM vernier (PMV) machines, with the working principle of flux modulation effect, have gained increasing attentions due to their high torque density. Owing to the uniformly distributed ferromagnetic poles (FMPs), the fundamental magnetomotive force induced by rotor PMs interact with...
COMET experiment is aiming to search for a muon to electron transition at J-PARC. It requires the muon beam with high intensity of 10$^{11}$µ$^−$/s. The muon beam is produced by using a series of superconducting solenoids. The solenoid magnet in which the production target is embedded, called as COMET pion capture solenoid, is estimated to be exposed to severe radiation such as the neutrons of...
Theoretical IPMSM control technique is complicated, and reliability is low, because of the changing parameters. Further, in case of general look-up table designing method which obtains torque characteristics(according to current and speed) or torque characteristics(according to magnetic flux through the entire control region), obtaining a precise result can be difficult and has the...
The third generation of electron cyclotron resonance (ECR) ion sources is in operation or under development in the world. The fourth generation ECR ion sources are expected to operate at a heating radio frequency greater than 40 GHz, requiring a higher confinement field. Such requirements provide the motivation to design the structure of the fourth generation ECR ion sources. The Nb3Sn wire,...
In this paper we present two design options for a tabletop liquid-helium-free, persistent-mode 1.5-T/70-mm MgB2 “finger” MRI for osteoporosis screening. Both designs, one with and the other without an iron yoke, satisfy the following criteria: 1) 1.5-T center field with a 70-mm room-temperature bore for a finger to be placed at the magnet center; 2) spatial field homogeneity of <5 ppm over a...
Homopolar synchronous machine (HSM) has a solid rotor with no permanent magnet, winding and any other components. Therefore, the HSM has the merits of high speed operation, high energy storage density, brushless excitation, reliable structure, etc. However, when the HSM is analyzed and optimized by finite element analysis (FEA), the 3-D magnetic flux distribution in the HSM leads to the great...
This paper presents a Rogowski coil which is utilized to accurately measure the current value in second-generation (2G) high temperature superconducting (HTS) coil in cryogenic environment. We demonstrate the structure and key materials of this Rogowski coil. To ensure the accuracy measurement of superconducting current in cryogenic temperature, this Rogowski coil is fabricated into closed and...
A quality control technique is proposed that enables numerical reconstruction of distortions occurred during the manufacture and assembly of the PF1 coil for the ITER machine. The technique utilizes field maps measured near the surface of every pancake and the entire winding pack when the warm coil is energized with a low current. The measured data are used to evaluate parameters of the coil...
The ITER magnet system consists of 18 toroidal field (TFC) coils, a central solenoid, 6 poloidal field coils and a set of correction coils. The TFCs provide the required toroidal field (≈5.3T at plasma radius R=6.2m) mainly needed to confine the plasma. Since the magnets are under manufacturing, non-conformity (NCR) and/or deviation requests (DR) can be provided by the manufacturers. Fast...
A novel quench detector and post-mortem system for superconducting insertion devices are developed. This module consists of two functional components: quench detection and output latch signals for interlock purpose, which is based on field-programmable gate array, and a data acquisition system based on a set of simultaneous sampling ADC modules. The data acquisition system has two concurrent...
A detected loss-of-flow accident (LOFA) in the cryogenic cooling circuit of the ITER superconducting magnets will initiate a series of actions aimed at guaranteeing the protection and the integrity of the magnets. In the case of the Toroidal Field (TF) coils, the protection strategy following a LOFA triggered by, for instance, the stop of the cold circulator, is foreseen to determine an...
The armature of a balanced armature receiver (BAR) is made by a soft magnetic material with a nonlinear B-H curve and a saturation value. Based on our previous research, the saturation of armature may affect the nonlinear magnetic characteristics, especial with a strong current or a big vibration displacement. As one of the nonlinear magnetic characteristics in electromagnetic field, the...
As an inherent nonlinear device, an analysis method of a balanced armature receiver (BAR) considering the nonlinearity, especial the nonlinear magnetic characteristics are important. From literature survey, the finite element method (FEM) could be considered as the most accurate analysis method. Thus, a mass of simulations with 3D FEM analyses are proposed in this paper to analyze the...
Muon ionization cooling is theoretically well understood but has never been fully demonstrated experimentally. Ionization cooling is regarded as an important technology both in terms of cost and performance for a Neutrino Factory and is absolutely essential for a Muon Collider. The MICE experiment (Muon Ionization Cooling Experiment), based at the Rutherford Appleton Laboratory in the UK, is...
Generally quench detection of high temperature superconducting (HTS) magnet is difficult compared with low temperature superconducting (LTS) magnet. Because normal zone propagation (NZP) velocity of HTS is slower than LTS. In order to detect the quench signal for HTS magnet, signal wires for voltage taps are needed. However, owing to its slow NZP velocity, the quench signal of HTS magnet is...
IPMSM is mainly used as the traction motor of HEV and EV, because it has the high torque density and the wide operating range. Especially the size limit of traction motor exists in HEV, because HEV system consist of the engine and the electric propulsion systems at limited space. Many studies have been conducted to maximize the torque of a single air gap IPMSM with the size constraints. In...
Pulsed electromagnetic blank holding system is a new developed facility using pulsed attractive Lorentz force as blank holding force for sheet metal forming process. The system consists of two electromagnetic coils series-connected and a RLC circuit energizing them. The key metrics of the system are the peak value and pulse width of the pulsed blank holding force. In this paper, an analytical...
The production of superconducting magnets involves tight tolerances and high precision assemblies, in order to achieve the requirements for their appropriate performance. It is therefore essential to have a strict control and traceability over the geometry of each part of the system, and also to be able to compensate possible inherent deviations coming from the production process. The...
The Ion Ring for the proposed Jefferson Lab Electron-Ion Collider require large aperture with high homogeneity, 1 T/s ramping, and significant beam losses. Two designs have been developed, both utilizing a cable-in-conduit (CIC) winding in which liquid helium flows within the conductor. Two alternative designs are being developed, with the same aperture, having maximum operating field of 3(6)...
Rare earth permanent magnet motors are used in many industrial fields because of the advantage of superior output power density. Currently, however, non-rare earth motors have been actively studied due to the instability of rare earth supply and price fluctuations. Example of non-rare earth motors includes a synchronous reluctance motor (SynRM), a wound rotor synchronous motor (WRSM), a...
When motor is in operation, harmonic components are inevitably included. Due to the harmonic components, experimental results of motor performance is different from that obtained from FEA analysis, which assumes there is no time harmonic components. However, time harmonic components should be considered in performance analysis process, since time harmonic has effect such as noise and loss.Time...
High-temperature superconducting magnetic energy storage systems (HTS SMES) have attracted significant attention for fast response and ensure a reliable power supply. However, the current carrying capacity of single superconducting tape often meets limitation for the large scale energy storage for HTS SMES applied in the power grid. Therefore, a composite superconductor with inherent helical...
The inverter system must be necessary for a high-temperature superconducting (HTS) synchronous motor control in any electric propulsion system such as ship, vehicle, and aircraft. HTS motors for electric propulsion are driven and controlled by pulse width modulation (PWM) input voltage with harmonics, which is made in voltage source inverter (VSI) by a various switching pattern. Therefore,...
High-temperature superconductors (HTS) have a much larger thermal margin than low-temperature superconductors (LTS) due to high critical temperature and high upper critical field. It allows HTS magnets to operate stably so as to tolerate very high heat loads due to radiation. Therefore research on development of HTS quadruple magnet is progressed widely. The Quadruple magnets are used for...
A permanent-magnet (PM) phase shifter is constructed for a tandem elliptically polarized undulator (EPU) at TPS. To increase a reproducibility of magnetic field and be installed in a limited space, a robust mechanical structure was designed and constructed. To decrease multipole errors and optimize magnetic field, algorithms of magnet sorting and magnetic field shimming were built and...
In many applications dipole magnets with coils having significant curvature are needed. This is particularly challenging for high temperature superconductors (HTS) as they are brittle. One application for curved HTS coils is the fragment separator dipole magnets for the Facility for Rare Isotope Beams (FRIB). These magnets operate in a high radiation environment and are subject to a high...
This paper presents core loss analysis of 5kW permanent magnet linear synchronous generator (PMLSG) with slotless stator. PMLSGs are widely used in various applications. Due to the advantages of high efficiency, high power density, and low maintenance cost. Moreover, slotless stator has the advantages of reducing the detent force and magnets barely impact the electrical steel’s saturation due...
A bearingless permanent magnet synchronous motor (BPMSM) is a new type of motor with the magnetic bearing function applied to the traditional permanent magnet synchronous motor. Besides of the simple structure, high efficiency, and high torque density, the BPMSM can operate with no friction, no wear, high-speed and high-precision, and so on, which show great potential application in many...
REBCO coated conductors has a layer structure composed of Cu, Ag, GdBCO, MgO and Hastelloy substrate. Although the REBCO conductors enables high field magnet designs, their critical current properties are sensitive to mechanical stress. Especially, the thermal stresses in the cooling process of the REBCO magnets may cause the delamination of the layer structure of the REBCO conductor. This...
Previous studies indicated that the use of high-temperature superconductor (HTS) sections in the highest field allows maintaining the magnetic flux in the central solenoid (CS) reducing the outer diameter compared to the nominal size specified by EUROfusion. A reduced outer diameter of the CS coil would provide the possibility to reduce overall size and cost of DEMO. The proposed winding pack...
The direct-drive wave energy converter (DD-WEC) system, using linear generator, are widely used for WEC. However, at the low direct-drive speed, how to increase the power density of the linear generator is the main objective of the researchers. Therefore, there are many linear generators have been investigated for DD-WEC. To solve the problem, a transverse flux hybrid field modulated linear...
High temperature superconducting magnets (HTS) suffer from slow quench propagation, have high thermal margin, and consequently require external energy extraction for quench protection. This is especially the case with such accelerator magnets where most of the magnet volume operates far away from its critical surface. Quench heaters and CLIQ, as the most promising quench protection systems...
Marine currents are more predictable than wind and solar power. Because there are only small fluctuations in current speed and stream location with minimal changes in direction, ocean currents may be suitable locations for deploying energy extraction devices such as turbines. The kinetic energy of marine currents can be converted in much the same way that a wind turbine extracts energy from...
Recently, MgB2 wire and YBCO wire have been widely used in superconducting generators. However, they have differences in terms of material characteristics, product performance, price, and the relevant cryogenic cooling system, which have a great influence on the design of superconducting generators. Therefore, it is necessary to compare which wire is better for superconducting wind turbine...
Hyper Tech will report on progress that has been made on designing helium-free MgB2 magnets for 1.5 and 3.0 T full body MRI systems, including mechanical, thermal and quench protection analysis, conductor development, jointing, and prototype test coil characterization and measurements. As an addendum, the development of low AC loss MgB2 conductors for motors and generator will be presented.
Hybrid wiggler for SR research program at the VEPP-4 was created in the Budker Institute of Nuclear Physics. The wiggler consists of ordinary poles with coils, which generate a spatially periodic magnetic field equal to 1.8 T. Also, permanent magnets are insertion between the poles for increasing magnet field up to 2.05 T. In this paper we present the design, calculations and magnetic...
The high temperature superconductor (HTS) direct current (DC) induction heater shows a great potential in improving the efficiency and heating quality, which has have been studied and validated in some laboratory-scale prototypes. Now, an industrial scale HTS DC induction heater with 1 MW is designed and manufactured in Shanghai Jiao Tong University, China. The heater is designed for aluminum...
High temperature superconducting (HTS) generator is attractively researched with the advantages of high efficiency, and small size compared with conventional generator. One of the big challenge is cooling down the temperature of HTS magnet to ensure the superconducting state. It can take a long time to reach a vacuum because of bulky cooling system. In order to improve the cooling performance...
Magnets wound with coated conductors are attractive for the applications to accelerator systems because of high magnetic field generation and easy cooling by using cryocooler. In accelerator systems, the time-dependent and precise magnetic fields are sometimes required. However, large magnetization in wide coated conductors deteriorates field qualities of magnets, and the temporal behavior of...
Recently, due to the rising issue of environmental pollution, secure process of rare earth material with high efficiency is increasing world wide. However, the price of the rare earth material has increased significantly by restriction of rare earth production in China, where more than 90% of rare earth material is produced. Therefore, non rare earth material, for replacing of rare earth...
The design of helical permanent magnet undulator with a period length of 24 mm for the production of circularly and linearly polarized radiation will be discussed. The helical permanent magnet undulator consists of four pairs of helically shaped Vanadium Permendur poles located between Neodymium Iron Boron magnet blocks. This magnet arrangement is expected to produce helical fields in the...
A new proton therapy facility (HTPTF) is under construction in Wuhan, China. The dipole magnet integral measurement system was designed for the beam transport system of the HTPTF. The design goal is to build a reliable, precise, automatic measurement system, and it is accurate enough to characterize the magnetic field quality of the dipole magnets in the beam transport system. The integral...
As the global helium crisis continues, the need for liquid-helium-free superconducting magnets continuously increases in the commercial sector of magnetic resonance imaging (MRI) systems. However, the conventional low temperature superconductor (LTS) magnets frequently experience unpredictable premature quenches, resulting in the extra usage of liquid helium before an MRI machine is delivered...
The superconducting dipole magnets of the Large Hadron Collider operate in a superfluid helium bath at 1.9K. As a part of the magnet quench protection system, each dipole magnet is equipped with a by-pass diode located in the helium bath. The connection between the superconducting magnet and the cold by-pass diode is made through a clamping system called “half-moon”, located at the lowest...
Princeton Plasma Physics Laboratory is currently developing a targeted superconducting magnet R&D program in support of its leading design studies of Fusion Nuclear Science Facility (FNSF) and Pilot Plant using the most promising magnetic confinement configurations including Spherical Tokamak and Stellarator. An innovative magnet design approach is required to ensure success of the FNSF,...
A proton accelerator requires a wide range of beam properties such as beam energy, beam current, beam repetition rate, and beam pulse width. The electron beam ion source (EBIS), which can perform short pulse operation up to 1 μs, can meet the diverse requirements of users by facilitating enhanced utilization efficiency and broad application area. Therefore, the purpose of this study is to...
The cooling of the ITER Toroidal Field (TF) coils winding pack is guaranteed by the circulation of supercritical Helium (He) in 134 Nb3Sn Cable in Conduit Conductor (CICCs) and in 74 channels devoted to the cooling of the Stainless Steel (SS) case supporting the winding pack. A simplified tool aimed at computing the temperature distribution and the He temperature in the cooling channels of the...
Generally, Nb3SN and NbTi wires are used widely in superconducting applications. However, these wires are expensive and have low critical temperature (Tc of Nb3SN=18 K, Tc of NbTi=9.8 K). To maintain the low-temperature condition, liquid helium is required continuously for cooling the wire and this causes lots of maintenance cost. However, MgB2 wire has higher critical temperature than Nb3SN...
The development and of magnetic billet heating with high temperature superconductor (HTS) coils provided energy benefits to the aluminum extrusion process, compared with conventional technologies. The magnetic billet heating technique by rotating aluminum rods in a magnetic field achieved large heating capacity with high efficiency in short time for an extrusion. Recently, in an industrial...
High-field magnets wound with REBCO tape and their application to NMR have undergone considerable research and development. NMR coil systems require a highly accurate field; i.e. homogeneous and temporally stable field. However, in case of REBCO coils, the screening current induced magnetic field spatially and temporally deteriorates the field quality.. The filamentization of REBCO tape...
A bearingless permanent magnet slice motor (BPMSM) has compact structure and high efficiency, which can realize the rotor magnetic suspension at five degrees of freedom. The rotor magnetic field oriented strategy can realize the decoupling control of torque and suspension force, but it is difficult to meet the high performance requirements of torque and suspension force. The theory and method...
The High Intensity Heavy-ion Accelerator Facility (HIAF) is a new major scientific infrastructure at the Institute of Modern Physics of Chinese Academy of Science (IMPCAS), which is expected to accelerate heavy ions to 12.0 GeV/u. To improve gradually heavy-ion beam energy, booster ring which is an important accelerator between i-linac and HFRS, is established for confine and deflect the heavy...
YBCO tapes are subjected to various stresses such as tension, compression, bending, twisting and fatigue in practical application. The influence of mechanical fatigue on the critical current decay behavior has been studied by several research teams. The impact of background magnetic field on the critical current degradation under tensile fatigue loading, however, has been rarely investigated....
Number of offshore wind farms is still increasing all over the world. The offshore wind power is greater than that on land. In addition there is no restriction of site and road for construction. However the offshore wind farm is expensive. Therefore the capacity in electricity per a wind turbine needs to be much larger than those on land and onshore. Especially, in Japan, there is so little...
A no-insulation (NI) winding technique is very promising to conduct a practical use of REBCO pancake coils by greatly enhancing the thermal stability. Many applications using the NI technique have been developed or constructed, such as a magnetic separation, a 1.3-GHz NMR, an over 40-T magnet, etc. So far, a lot of measurement data proved a high thermal stability of test magnets through...
The fluorine-free metal organic decomposition (FF-MOD) is one of the most promising methods for preparing REBa2Cu3Oy (REBCO, RE: rare earth elements) coated conductors because the simple chemical reaction to form textured REBCO phases is completed in a short time without any necessity of vacuum chambers or high power laser devices. However, reproducibility is...
The trifluoroacetate metal-organic decomposition (TFA-MOD) process is a non-vacuum process. Therefore, this process for REBa2Cu3Oy (RE: rare earth) coated conductors (MOD-REBCO) is useful from a cost point of view. Recently, it has been reported that the critical current density (Jc) in liquid nitrogen temperature can be increased effectively by reducing once-coat-layer-thickness in the...
Ultra-high field magnets are becoming fundamental in brain research in order to satisfy the higher requirements in tissue contrast, spectral resolution and signal to noise ratio. ASG is putting a lot of effort to be competitive in this sector. After a 7 T conceptual design (1) , now ASG is working on an 11.74 T MRI magnet for the Gachon University GIL Hospital.In this project, ASG has the...
The variation of the magnetic flux density due to shielding current attenuation causes negative influence on temporally stable magnetic flux density required at the center of high-resolution MRI magnets. We have already clarified the relationship between the maximum current in an overshooting process and the shielding magnetic flux density attenuation and established the estimation method of...
FAIR (Facility for Antiproton and Ion Research), planned to be built at the site of GSI, will include the 300 Tm fast-ramping heavy ion synchrotron SIS300. In the frame of collaboration in FAIR project IHEP has developed, produced and tested two prototypes of a SIS300 fast cycling superconducting quadrupole. The main parameters of the quadrupole are: 45 T/m central gradient, the gradient ramp...
The screening current-induced field (SCF) is well known to be an intrinsic problem for an REBCO magnet to have an NMR-quality field homogeneity. According to recent studies, the SCF in an REBCO magnet may be effectively reduced by the current sweep cycle method that requires “overshooting” in the magnet current. When an REBCO magnet is operated at a “low” temperature and thus has a large...
This work describes magnetic, mechanical, and thermal Finite Element Modeling (FEM) studies in support of a whole body 3 T MRI magnet based on conduction cooling. As a strand, both 1G and 2G MgB2 conductors were considered. An optimization code to design the main coil segment layout and winding size was used. Thermal FEM modeling was used to estimate the temperature gradient on the coils in...
A superconducting cyclotron is designed and under construction at China Institute of Atomic Energy to provide 230 MeV proton beam for cancer therapy. The fine machining of the main magnet will be finished soon and then the iterative shimming process is normally performed to get the ideal isochronous field, which requires the relative measured field error should be within 10-4. A searching coil...
Several joint-less coil structures were developed in the past decade that allow the coil made of HTS coated conductors operate in persistent current mode (PCM) at 77 K. The PCM coils could operate as the main magnet or shielding coil for small MRI/NMR or in maglev at 77 K to simplify the cryogenic system and lower the cost. While after the PCM coil is magnetized, the field trapped in the coil...
Since several years the Institute for Beam Physics and Technology (IBPT) of the Karlsruhe Institute of Technology (KIT) is collaborating with its industrial partner Babcock Noell GmbH (BNG) in a R&D program on superconducting undulators (SCUs). At present the collaboration is primarily working on a SCU with a period length of 20 mm (SCU20). This device is foreseen to be installed at ANKA, the...
The consortium of Russian researchers is discussing further works on new fusion devices. One of the goals is the development of superconducting magnets of the demonstration hybrid facility - Fusion Neutron Source (DEMO FNS) based on the tokamak concept with the conventional aspect ratio ~3 [1, 2]. This device should have 5 T on the plasma axis and ~12 T on the toroidal coils. Because of high...
This paper studied on the comparison of traction motor for same size with sintered rare-earth magnet and bonded Dy free magnet. We designed PMASynRM with bonded Dy free injection magnet by changing only rotor and experimented to verify performance at the same size IPMSM with sintered rare-earth magnet. We simulated the magnetic orientation of the injection Dy free magnet to make the...
Princeton Plasma Physics Laboratory is currently leading the design studies of Fusion Nuclear Science Facility and pilot plants based on the most promising magnetic confinement configurations including the low aspect ratio Spherical Tokamaks. An innovative magnet design approach is needed to close the gap between rapid advances in High Temperature Superconductor (HTS) and the maximal fusion...
The Normal Zone Propagation Velocity (NZPV) and quench are areas of intense research for High Temperature Superconductors (HTS). While normal zones travel with speeds in the order of magnitude of m/s in Low Temperature Superconductors (LTS), in HTS coated conductors this speed is in the order of cm/s. This makes ensuring a quick and uniform quench, and thereby the cryostability of tapes,...
Klystron beam focusing system with permanent magnets can increase reliability of RF power system and reduce its power consumption. A prototype magnet system with ferrite magnets was fabricated for a L-band 800 kW klystron. The power test of the klystron with the prototype magnet system has proved the feasibility of the prototype. However, multi-pole transverse magnetic field components...
An undulator with a strong magnetic field in a short period will become an important light source device in an accelerator storage ring or a free-electron laser. The bulk YBCO can be used to construct a high-temperature-superconducting undulator with staggered array structure. The bulk YBCO of diameter 32 mm and thickness 2.5 mm was constructed and assembled as a staggered magnet array. The...
Fault-tolerant permanent-magnet (FTPM) machines provided high efficiency, good fault-tolerant capability and high reliability. The electromagnetic torque of FTPM machine contains both permanent magnet (PM) and reluctance torques. At high speed operation condition, high reluctance torque can not only help prevent machines out of control when using flux weakening control method but also...
The shielding-current-induced field (SCIF) of coated-conductor magnets has been studied mainly for dc magnets. In dc magnets, E-J characteristics of coated conductors can influence their field stabilities, because shielding currents should decay by the finite resistivity, i.e. E divided by J. In magnets generating time-variant magnetic fields, the field ramp-up/down rates as well as E-J...
It is well known that the second generation high-temperature superconductor (HTS) tapes have local inhomogeneities of magnetic and current-carrying characteristics. These features of the material often limit the length of tape suitable for applications. The main purpose of present work is to improve the magnetic and transport characteristics of 2G HTS tapes by creating an ordered lattice of...
A superconducting magnet commonly used in current MRI systems should be operated in the persistent current mode (PCM) to yield a high-resolution level that requires a magnetic field drift of less than 0.01 ppm/h. To acquire the required field homogeneity as a function of time, the availability and even reproducibility of a superconducting joint technique enabling the PCM of the magnet should...
Abstract- On the basis of the high power (MW-level) and high torque density requirements for large ship Integrated Full Electric Propulsion (IFEP) system, the optimal third-order harmonic shaping method for parallel magnetized direct-drive surface-mounted permanent magnet (SPM) machine is developed in this paper. In contrast to conventional surface-mounted magnet pole, the sinusoidal...
It was declared [1] that large superconducting winding will be saved from current degradation resulting from mechanical perturbations, if the winding has strong and rigid supporting structure, and each turn is rigidly fixed transmitting its force directly to the structure. The superconductor itself shouldn’t be used as a structural material. So far the only option was proposed that...
Ocean wave energy has a higher energy density than other renewable resources such as solar, wind, and tide energy. In recent years, a various ocean wave energy extraction systems have been proposed and established. But the average speed of ocean wave is generally slow. This will lead the traditional linear generator with disadvantages of large weight and low power density. In order to solve...
There are two major problems for introducing HTS-MRI magnets. One is a long-lasting attenuation of screening current induced on the superconducting tapes at the initial excitation. The screening current affects the MRI field stability both temporally and spatially. Another is that it is by now difficult to realize a superconducting junction of REBCO tapes and a superconducting switch for the...
A novel separated pole-piece type ferrite magnet motor (FMM) is comprises pole-pieces and webs separated from each other in order to maximize its magnetic performance and to minimize leakage flux. However, since such disconnected pole-pieces and webs are constrained only by end plates and rivets, the motors are vulnerable in terms of mechanical integrity at high rotating speeds (and thus under...
Mu2e experiment at Fermilab is set out to search for charged-lepton flavor violation by looking for muon to electron conversion in the field of the nucleus. The concept of the experiment is to generate low momentum muon beam, stopping the muons in a target and measuring the momentum of the conversion electrons. The implementation of this approach utilizes a complex magnetic field: graded...
The system architecture of a fusion reactor demands an enhanced magnetic field and downsizing to improve plasma-confinement and reduce the difficulties in construction. Since an electromagnetic force induced by a magnet system is proportional to the square of the magnetic field intensity ratio, the stress on the magnet system can be extremely severe. For FFHR, a helical fusion reactor, several...
FEA simulation software OPERA 3D is used to develop a geometric cavity feature on the pole face at the beam entry and exit points of a dipole magnet. This cavity is incorporated into a prototype magnet designed at Stangeness Industries to improve field homogeneity along the beam arc to 0.1%. The magnet design handles beams entering at different angles, positions and beam energies. The...
Quench detection is important for the application of the high-temperature superconducting (HTS) tape, especially REBCO tape. However, there is a serious issue that voltage drop is too small to detect quench due to the small normal zone propagation velocity (NZPV) in HTS. To address this issue, we have proposed a quench detectable LTS/HTS hybrid tape consisting of the low-temperature...
The discovery of superconductivity in iron-pnictide compounds in 2008 raised the prospect of finding high-temperature superconductivity in materials other than cuprates and a great deal of research has been carried out towards practical implementation in thin film, wire and bulk forms. Bulk superconducting materials, in particular, can be used as super-strength, trapped field magnets (TFMs)...
In the framework of the European-Japanese project JT-60SA, quench tests are performed for each one of the 18 NbTi superconducting Tokamak Toroidal Field (TF) coils in a Cold Test Facility at CEA Saclay. While launching these experimental quench tests, the conductors’ Tcs are reached by progressively increasing the inlet helium temperature so as to trigger a fast discharge of nominal current...
The toroidal field (TF) magnet in Tokamak system is required generate a high-steady field to confine and shape the high-temperature plasma. To secure high current density and high thermal stability, the no-insulation(NI) winding technique is used in the fabrication of TF magnet. During plasma operation, heat generated in the TF magnet due to the interaction with central solenoid(CS) coils,...
The JT-60SA Toroidal Field Coils (TFC) are currently being manufactured in Europe, and their assembly is progressing at full speed in QST, Naka. As part of their final acceptance, the coils are tested in working conditions and at full current in a dedicated facility in Europe. To help defining the cool down strategy for the testing of the TFCs, and also to anticipate their behavior during the...
One of the key systems of a fusion device is its magnet system producing high magnetic fields to confine plasma. The main component of the magnet system of a tokamak device consists of toroidal field (TF) coils, poloidal field (PF) coils and central solenoid (CS) coils. The shape of the TF coil has a big impact on its structural performance. When the shape is not mechanically optimized the...
High temperature superconductors (HTSs) are developed for applications in HTS power devices such as power transmission cables, transformers, superconducting fault current limiters (SECLs) superconducting magnetic energy storage (SMES). Over-current performance of YBCO tapes at power frequency has been well studied by previous researches. However, in a power gird, superconducting apparatus...
A 1.5 T cryogen free superconducting magnet for a dedicated orthopedic MRI of human extremities was developed and tested. The magnet has a compact cryostat cooled by a pulse tube coldhead with cooling power of 1 W at 4.2 K. The warm bore of a cryostat is 325 mm in diameter, 600 mm in length. Cost effective NbTi wire was used for making superconducting coils. The magnet is actively shielded....
In this work we have studied the critical properties of YBa2Cu3O7-δ thin films. The studied sample YBa2Cu3O7-δ is a monocristalline thin film deposited by the ablation laser method on the surface (001) of a SrTiO3 substrate. We have examined the variation of critical density Jc as a function of temperature for different values of a fixed magnetic field. This investigation shows that, in the...
Tracked inspection robots is a special robot to replace or assist of manual inspection, has great application prospects. Linear permanent magnet machine with primary-segmented is a good choice which can motion on the long distance without the use of gears. In this paper, adopting polar transformed subdomain modeling for predicting the magnetic field and forces in primary-segmented permanent...
In recent years, magnesium diboride (MgB2) has been regarded as one of the promising candidates for the development of MRI magnets owing to its critical temperature of 39 K, which allows magnets to be operated without the use of liquid helium (LHe), unlike their low-temperature superconductor counterparts. Prior to the development of the LHe-free MgB2 MRI magnet, it is essential to investigate...
The neutrino mass experiment KATRIN recently operated its complete chain of the superconducting magnets for the first beam test. A Magnet safety system (MSS) for the 16 m long source magnet system has been installed for quench detection and protection of the superconducting magnets. They are cooled by a liquid helium bath at 4.5 K. The magnet system consists of seven main superconducting...
Lawrence Berkeley National Laboratory (LBNL) in collaboration with the Institute of Modern Physics (IMP) is developing a Nb3Sn based superconducting magnet system for a fourth-generation ECR source, with a goal of achieving the field required for operating at the microwave frequency of 45 GHz. The magnet system is composed of one sextupole magnet and three solenoids of different sizes...
This paper discusses the design of the quench protection for a conduction-cooled MgB2 magnet system that will be used for magnetic density separation (MDS). First, an extensive literature review is made of currently available quench detection and - protection methods, which are discussed in a structured way in terms of merrits and challenges. Next, the measured normal zone propagation...
The research and development on the applications of REBCO superconducting coil to the high field magnets for NMR, MRI, accelerator and so on are in progress. In these application, the magnets need to create highly homogeneous and temporally stable field. However, the screening currents lead to the serious problem in REBCO magnets for the applications required very high field quality. Then,...
We have proposed a method for effectively repairing locally defective or damaged HTS coated conductors produced during manufacturing HTS coated conductor or coil winding for magnet applications using superconducting patch. The superconducting patch was fabricated by separating the metal substrate from the commercial HTS coated conductor using the interface delamination phenomenon. And it has...
With the energy crisis and environmental problems becoming increasingly prominent, the utilization of renewable energy is showing an accelerated attention. Compared with wind and solar power, ocean wave energy has many advantages such as high energy density, large amount and being easy to forecast. Direct-drive ocean waves energy conversion system(WEC) has a simple structure and higher...
The floating wind power generation is an important trend of the wind power generation on the sea, paid more attentions by the researchers around the world. The direct-drive vertical axis wind turbines (DVAWT) gives an important development direction for the floating wind power generation. In order to improve the starting performance and output power of the DVAWT, a hybrid excitation maglev...
In order to reduce the heavy rare earth element, permanent magnet are continuously developing. Especially, maintain of high coercive force is a very important technology in motors that mainly use high currents. In addition, since the price of heavy rare earth element is high, the use of the rare earth element is minimized so that the price competitiveness of the motor is obtained. In this...
With the rapid develop of energy crisis and environmental problems, the utilization of renewable energy is attracting an increasing attention in the world. Compared with the wind and solar power, ocean wave energy has many advantages, such as high energy density, large amount and being easy to forecast, etc. Therefore, a various ocean wave energy extraction systems have been proposed and...
Screening currents induced in superconducting wires are well known as a critical issue upon NMR/MRI magnet operations. It invokes an irregular field and downgrades the magnetic field homogeneity of NMR/MRI magnets. Especially, in REBCO magnets, screening currents have a strong effect on an on-axis magnetic field due to the shape of REBCO tapes. Therefore, in order to reduce the screening...
A bearingless permanent magnet synchronous motor (BPMSM) is a new type of motor, which inserts functions of the magnetic bearings into the traditional permanent magnet synchronous motor, and realizes the steady suspension and rotation of rotor at the same time. Because of its advantages, such as high efficiency, high power factor, good control performance, no mechanical contact, non-wear,...
In order to control and reduce the electromagnetic vibration of induction motors, the stress in motors cores, which is the inherent reason of vibration, should be computed accurately. Stress in induction motors is mainly generated from Maxwell electromagnetic force between the stator and rotor under the rotational magnetization excitation. The non-oriented silicon steel in motors shows...
The Brushless DC(BLDC) motor is getting more widely used in home appliances, vehicle and industry for its easy control method and low cost. For proper control of the BLDC motor, it is designed to have trapezoidal Back-EMF wave form and the square wave current is applied to its phase current which has instantaneous switching in its wave form. Although, in low speed or low phase current, the...
The LASA Lab. (INFN, Milan) is developing a a new type of superferric magnets suitable to arbitrary multipole order which we refer to as Round Coil Superferric Magnets (RCSM). It is based by the previous proposal of I. F. Malyshev and V. Kashikhin. This type of magnets is suitable for strain-sensitive superconductors, because it only uses a single round coil, which has a large bending radius,...
In this paper a novel magnetic field modulation linear primary permanent magnet synchronous motor (LPPMSM) is proposed, which is originated from brushless electrically excited synchronous machine ( BEESM ) .LPPMSM have short primary (rotor side), long secondary structure. The primary side consists of an iron core with salient teeth wound which 3-phase armature windings and permanent magnets...
The energy efficiency of novel high temperature superconductor (HTS) direct current (DC) induction heating method can approach to 90%, due to the loss-free of superconducting coil in DC operation. Now a MW-scaled HTS DC induction heater is designed and manufactured. The magnet is coulped with iron core, which helps to guide the magnetic flux and generate more suitable magnetic field for...
This study is about the cooling of the superconducting wire by spraying the liquid nitrogen. In this study, the superconducting wire was cooled under the spray cooling condition, and a current flow test was conducted. In addition, the operating range of the superconducting wire was presented under the spray cooling condition of the liquid nitrogen. For this, a low temperature container with a...
This paper discusses a motor that was designed to satisfy the size constraints of system by using ferrite magnet and has the same performance as rare-earth magnet motor. In general, the size of the motor is increased in order to meet the same performance of motor using a ferrite magnet, because of its very low energy density compared to the rare-earth magnet. Thus this paper researched the...
In this report we present results of analysis of pinning force as well as pinning energy in PLD $GdBa_2 Cu_3 O_{7-x} $ coated conductors doped by $BaSnO_3$ and $BaZrO_3$. Concentrations of both additions in the studied samples have varied from 0 to 18 mole per cent. For all samples we measured magnetization curves in the range of temperature 4,2-77 K and magnetic field up to 14 T. Dependencies...
Many applications of YBCO tapes operate under external magnetic fields, hence it is necessary to investigate the in-field angular dependence of the critical current density of the coated conductors. In this paper, five commercial YBCO tapes with different microstructure that produced by three different manufacturers are chosen, which have width of 2mm, 4mm, 6 mm or 12mm. The in-field critical...
Sm1+xBa2Cu3+yO7-d (SmBCO) coated conductors were fabricated by reactive co-evaporation method in the EDDC (Evaporation using Drum in Dual Chambers) deposition chamber. The structure of SmBCO coated conductor was Ag/SmBCO/LMO/MgO/Y2O3/Al2O3/Hastelloy. The deposition system was composed of dual chambers: reaction chamber and evaporation chamber. Superconducting materials of Sm, Ba, and Cu were...
Cogging Torque is essential torque component on permanent magnet motor having teeth and slots and also this is an important characteristic of some applications such as electrical steering motor which requires precision position control and lower acoustic noise. There had been investigated variety techniques to reduce cogging torque during several decades and most of them show common feature...
The Mu2e experiment at Fermilab is designed to search for charged-lepton flavor violation by looking for muon to electron conversions in the field of the nucleus. The concept of the experiment is to generate a low momentum muon beam, stopping the muons in a target and measuring the momentum of the conversion electrons. The implementation of this approach utilizes a complex magnetic field...
The joint-less coil is wound by ‘‘wind-and-flip’ technique. Due to the absence of resistive joint, the coil enable the current to flow in an absolutely superconducting closed loop, therefore it can load a DC current persistently without power supply. Therefore, the coil shows a great potential on MRI/NMR, permanent magnet and rotor magnet of HTS machines. This paper is to study the trapped...
IEEE Standard 37.96-2000, Guide for AC Motor Protection, recommends the use of overcurrent relays for overload and locked rotor protection. Because of the familiar use of overcurrent protection, little attention is paid to the nature of motor thermal limit curves and their relation to winding temperature in an induction motor. Although thermal limit curves are defined in IEEE Standard...
Operation stability study for a large-scale superconducting magnet is of particular importance to protect the magnet from permanent damage. Especially, for a fusion magnet, severe heat load by AC loss needs to be effectively removed during operation to achieve required temperature margin. A unique feature of KSTAR PF (poloidal field) magnet is that all the liquid cryogen inlets and outlets of...
In the framework of the European fusion program for energy, EUROfusion funds the studies for the future fusion power demonstrator reactor DEMO. CEA is involved on the conceptual design of the superconducting conductors for the Toroidal Field (TF) and Central Solenoid (CS) magnets. The CEA design proposal corresponds to Wind and React Nb3Sn pancake-wound coils using Cable-In-Conduit Conductors...
The superconduting tapes are widely used in fault current limiters for AC power systems. However, they are still in the study in the HVDC situation as it has a lot of differences compared with the AC situation. In the AC situation we have 45ms-60ms to shut down the circuit breaker so the current flows through the superconduting tape would be two or three times of the critical current of the...
This paper presents a torque maximization method to increase output torque without deteriorating the torque ripple in radial magnetized surface-mounted permanent magnet (SPM) machine having sinusoidal shaped pole by using third-order harmonic (Sine+3rd) shaping method. The optimal value of third-order harmonic injected into sinusoidal shaping can be either scanned out by finite element...
There is a strong demand for higher field magnets in the various field of science. The development of solenoids capable of generating high magnetic fields of 20–30 T has been ongoing in major high-field laboratories in the worldwide. In the field of high energy accelerator, a 20 T dipole magnet is listed as a candidate for the bending magnet of the Future Circular Collider and the proposed...
MRI is widely used for diagnosis and characterization of many diseases and injuries. It has immense potential for early diagnosis of cancer through well-patient screening, but that potential is largely unrealized because the cost of dye-contrast MRI is $thousands and it is not affordable to screen well patients. We have employed a new methodology of magnetic design to project a domain of...
As a new kind of magnetic material, nano-crystalline alloys have high permeability and excellent loss characteristics, and measurement of high frequency magnetic properties of nano-crystalline alloys have great significance on the development of high frequency and high power density transformer. Since the permeability is very high, not only the external field even with small values but also...
The EU-funded EcoSwing project aims at demonstrating world's first superconducting low-cost and lightweight wind turbine drivetrain demonstrated on a large-scale wind turbine. This prototype generator is planned to operate in the second half of 2017. The main design considerations for this synchronous generator will be explained. Further the focus is on the superconductive coils made of 2G...
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